编译原理end
【摘要】 #include<bits/stdc++.h>using namespace std; const int max_word = 505;//关键字 const char keyWord[13][20] = {"main","if","else","do","while","for","switch","case","int","double","float","...
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#include<bits/stdc++.h>
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using namespace std;
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const int max_word = 505;
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//关键字
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const char keyWord[13][20] = {"main","if","else","do","while","for","switch",
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"case","int","double","float","long","void"};
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//单词表
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struct Word{
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char value[20];//单词值
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int type;//单词种类
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int line;//行号
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}w[max_word];
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//四元式
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struct si_Yuan{
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string op;//运算符
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string s1;
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string s2;
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string res;//结果
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}sy[105];
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//文件流
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FILE *fin,*fout;
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int line = 1;
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char token[12];//存放单词
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int flag = 0;//判断是否获取字符
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int flag1 = 0,flag2;//flag1判断是否项已经产生miss错误;
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int e = 0;//错误个数
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int sy_num = 0;//四元式的个数
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string op,s1,ss1,s2,res,res1,res2,op2,op1;
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int op_num = 0,op_num1 = 0;//运算符的个数
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int sy_id;//四元式的序号
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string var[300];//已经声明的变量
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int var_num = 0;//声明变量的个数
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int sent_id;//判断if,while语句
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string equ[300];//=
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int a,b,c;
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int equ_num = 1; //=个数
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int cnt = 0,token_num = 0;//当前字符
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int row = 1;//当前行数
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char ch;
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char ch1;
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int word_num = 0;//单词的总个数
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int word_cnt = 0;
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string temp;
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char str_int[20];
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stack<string>word_stack;//保存
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stack<string>op_stack;
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//程序
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void S();
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void P();//(){分程序}
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void P1();//分程序
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void A();//变量说明部分
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void B();//语句部分
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void B1();
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int C();//变量说明
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void D();//标识符表
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void D1();
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void E();//标识符
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void F();//字母
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void G();//数字
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void H();//语句
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void I();//赋值语句
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void J();//条件语句
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void K();//循环语句
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int L();//关系运算符
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void M();//表达式
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void M1();
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void N();//项
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void N1();
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int O();//加法运算符
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int Q();//乘法运算符
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void R();//常量
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void S();//无符号整数
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void T();//数字序列
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void W();//复合语句
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void X();//条件
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void Y();//语句1
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void Z();//因子
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//构造四元式
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void siYuan(string op,string s1,string s2,string res)
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{
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sy[sy_num].op =op;
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sy[sy_num].s1=s1;
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sy[sy_num].s2=s2;
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sy[sy_num].res=res;
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sy_num++;
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}
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void printFour()//输出四元式
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{
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ofstream out("sy.txt");
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int i;
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for(i=0;i<sy_num;i++)
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{
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cout<<i<<":\t("<<sy[i].op<<",\t"<<sy[i].s1<<",\t"<<sy[i].s2<<",\t"<<sy[i].res<<")"<<endl;
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out<<i<<":\t("<<sy[i].op<<",\t"<<sy[i].s1<<",\t"<<sy[i].s2<<",\t"<<sy[i].res<<")"<<endl;
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}
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}
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void error(string err)//报错，定位到错误行
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{
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cout<<"第"<<w[word_cnt].line<<"行出错!\t";
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cout<<err<<"\n";
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e++;
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}
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//检查变量是否被声明
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void is_say(string a)
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{
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int i;
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for(i=1;i<=var_num;i++)
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{
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if(a.compare(var[i])==0)
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{
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break;
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}
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}
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if(i>var_num)
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{
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cout<<"第 "<<w[word_cnt].line<<" 行出错！\t";
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cout<<w[word_cnt].value<<" 没有被声明 !"<<endl;
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e++;
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}
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}
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void init_token(){
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int i;
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for(i = 0;i < 12;i++){
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token[i] = NULL;
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}
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}
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int judge_token(){
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init_token();
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if(flag == 0){
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ch = getc(fin);
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}
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flag = 1;
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while(ch == ' ' || ch == '\t' || ch == '\n'){
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if(ch == '\n'){
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row++;
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}
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ch=getc(fin);
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}
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token_num = 0;
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if((ch>='a' && ch <= 'z') || (ch >= 'A' &&ch <= 'Z')){
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//可能为标识符或者变量名
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while((ch>='a' && ch <= 'z') || (ch >= 'A' &&ch <= 'Z') || (ch >= '0' && ch <= '9')){
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token[token_num++] = ch;
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ch = getc(fin);
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}
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token[token_num++] = '\0';
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for(int i = 0;i <13;i++){
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if(strcmp(token,keyWord[i]) == 0){
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//3为关键词
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return 3;
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}
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}
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//2为标识符
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return 2;
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}
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//是数字
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else if(ch >= '0' && ch <= '9'){
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while((ch >= '0'&& ch <= '9') || ch == '.'){
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token[token_num++] = ch;
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ch = getc(fin);
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}
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return 1;
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}
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else{
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token[token_num++] = ch;
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switch(ch){
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case '(': ch = getc(fin); return 16;
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case ')': ch = getc(fin); return 17;
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case '{': ch = getc(fin); return 33;
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case '}': ch = getc(fin); return 34;
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case '+':
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ch = getc(fin);
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if(ch == '+'){
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token[token_num++] = ch;
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ch = getc(fin);
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return 29;
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}
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else{
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return 18;
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}
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case '-':
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ch = getc(fin);
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if(ch == '-'){
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token[token_num++] = ch;
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ch = getc(fin);
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return 30;
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}
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else{
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return 19;
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}
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case '*':
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ch = getc(fin);
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if(ch == '/'){
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token[token_num++] = ch;
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ch = getc(fin);
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return 32;
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}
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else{
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return 20;
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}
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case '/':
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ch = getc(fin);
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if(ch == '*'){
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token[token_num++] = ch;
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ch = getc(fin);
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return 31;
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}
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else{
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return 21;
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}
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//这里要重新编码
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case '=':
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ch = getc(fin);
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if(ch == '='){
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token[token_num++] = ch;
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ch = getc(fin);
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return 23;
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}
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else{
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return 22;
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}
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case '>':
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ch = getc(fin);
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if(ch == '='){
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token[token_num++] = ch;
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ch = getc(fin);
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return 24;
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}
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else{
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return 23;
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}
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case '<':
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ch = getc(fin);
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if(ch == '='){
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token[token_num++] = ch;
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ch = getc(fin);
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return 26;
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}
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else{
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return 25;
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}
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case ';': ch = getc(fin); return 27;
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case '"': ch = getc(fin); return 28;
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case '!':
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ch = getc(fin);
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if(ch == '='){
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token[token_num++] = ch;
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ch = getc(fin);
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return 37;
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}
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else{
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return 36;
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}
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case '#': ch = getc(fin); return -2;
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case ',': ch = getc(fin); return 35;
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case EOF: return -1;
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default: ch = getc(fin); return -10;
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}
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}
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}
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void getWord(){
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int temp;
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while(1){
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temp = judge_token();
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if(temp==-1){
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break;
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}
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switch(temp){
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case -10:
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//cout<<"第 "<<row<<" 行出现错误."<<endl;
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error("word has a mistake");
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w[word_num].type = -1;
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strcat(w[word_num].value," ");
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word_num++;
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break;
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case -1:
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return;
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default:
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w[word_num].type = temp;
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w[word_num].line = row;
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strcpy(w[word_num].value,token);
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word_num++;
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//cout<<"<"<<temp<<","<<token<<">"<<endl;
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break;
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}
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}
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}
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//程序
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void S(){
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if(strcmp("main",w[word_cnt].value)){
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error("miss main");
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word_cnt--;
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}
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word_cnt++;
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if(strcmp("(",w[word_cnt].value)){
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error("miss (");
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word_cnt--;
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}
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word_cnt++;
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if(strcmp(")",w[word_cnt].value)){
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error("miss )");
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word_cnt--;
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}
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word_cnt++;
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if(strcmp("{",w[word_cnt].value)){
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error("miss {");
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word_cnt--;
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}
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word_cnt++;
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P();
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if(strcmp("}",w[word_cnt].value)){
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error("miss }");
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word_cnt--;
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}
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op = "#";
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s1 = "";
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s2 = "";
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res = "";
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siYuan(op,s1,s2,res);
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cout<<"There are "<<e<<" mistakes in total."<<endl;
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}
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//分程序
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void P(){
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A();//变量说明部分
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if(strcmp(";",w[word_cnt].value)){
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error("miss ;");
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word_cnt--;
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}
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word_cnt++;
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B();//语句部分
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}
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//变量说明部分
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void A(){
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if(C()){
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var[++var_num] = w[word_cnt].value;
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D();
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}
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else{
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D();
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}
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}
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//变量说明
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int C(){
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if(strcmp(w[word_cnt].value,"int")){
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error("miss int");
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return 0;
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}
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word_cnt++;
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return 1;
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}
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//标识符表
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void D(){
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if(w[word_cnt].type != 2){
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error("denoter has a error");
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}
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word_cnt++;
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D1();
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}
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//子标识符表
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void D1(){
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if(strcmp(w[word_cnt].value,";") == 0){
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return;
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}
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if(strcmp(w[word_cnt].value,",")){
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error("miss ,");
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word_cnt--;
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}
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word_cnt++;
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var[++var_num] = w[word_cnt].value;
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if(w[word_cnt].type!=2){
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error("denoter has a error");
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}
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word_cnt++;
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D1();
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}
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//语句部分
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void B(){
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H();
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B1();
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}
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//子语句部分
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void B1(){
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if(strcmp(w[word_cnt].value,";") == 0){
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word_cnt++;
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H();
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B1();
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}
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else if(strcmp(w[word_cnt].value,"}") == 0){
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return;
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}
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else{
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error("miss ;");
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}
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}
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//语句
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void H(){
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cout<<"H()"<<endl;
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cout<<w[word_cnt].value<<endl;
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if(w[word_cnt].type == 2){
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op_num = 0;
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is_say(w[word_cnt].value);
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word_stack.push(w[word_cnt].value);
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word_cnt++;
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I();
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}
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else if(strcmp(w[word_cnt].value,"if") == 0){
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op_num = 0;
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J();
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}
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else if(strcmp(w[word_cnt].value,"while") == 0){
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op_num = 0;
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a = sy_num;
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K();
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op = "go";
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s1 = "";
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s2 = "";
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stringstream sss;//int 转 string
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sss<<a;
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sss>>res;
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siYuan(op,s1,s2,res);
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//修改while跳转的序号
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stringstream sss2;
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sss2<<sy_num;
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sss2>>sy[sent_id].res;
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}
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else{
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error("extra fuhao");
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}
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}
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//赋值语句
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void I(){
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if(strcmp(w[word_cnt].value,"=") == 0){
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word_cnt++;
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//word_stack.push(w[word_cnt].value);
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M();
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if(e > 0){
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return;
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}
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if(op_stack.size() > 0){
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op = op_stack.top();
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op_stack.pop();
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s2 = word_stack.top();
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word_stack.pop();
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s1 = word_stack.top();
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word_stack.pop();
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res = word_stack.top();
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word_stack.pop();
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siYuan(op,s1,s2,res);
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}
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else{
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s1 = word_stack.top();
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word_stack.pop();
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res = word_stack.top();
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word_stack.pop();
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siYuan("=",s1,"",res);
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}
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}
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else{
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error("miss = ");
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word_cnt--;
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}
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}
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//if语句
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void J(){
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cout<<"J()"<<endl;
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if(strcmp(w[word_cnt].value,"if")){
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error("miss if");
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word_cnt--;
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}
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word_cnt++;
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if(strcmp(w[word_cnt].value,"(")){
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error("miss (");
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word_cnt--;
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}
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word_cnt++;
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//word_stack.push(w[word_cnt].value);
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X();//条件
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sent_id = sy_num;
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if(op_stack.size() > 0 && e == 0){
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op = op_stack.top();
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op_stack.pop();
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s2 = word_stack.top();
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word_stack.pop();
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s1 = word_stack.top();
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word_stack.pop();
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siYuan(op,s1,s2,res);
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}
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if(strcmp(w[word_cnt].value,")")){
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error("miss )");
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word_cnt--;
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}
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word_cnt++;
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//四元式置为空
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op = "";
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s1 = "";
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s2 = "";
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res = "";
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Y();//语句1
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stringstream ss;
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ss<<sy_num+1;
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ss>>sy[sent_id].res;
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-
sent_id = sy_num;
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op = "go";
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s1 = "";
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s2 = "";
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res = "";
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siYuan(op,s1,s2,res);
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if(strcmp(w[word_cnt].value,"else")){
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error("miss else");
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word_cnt--;
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}
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word_cnt++;
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Y();
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stringstream ss2;
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ss2<<sy_num;
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ss2>>sy[sent_id].res;
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}
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-
//while语句
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void K(){
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cout<<"K()"<<endl;
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if(strcmp(w[word_cnt].value,"while")){
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error("miss while");
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word_cnt--;
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}
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word_cnt++;
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if(strcmp(w[word_cnt].value,"(")){
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error("miss (");
-
word_cnt--;
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}
-
word_cnt++;
-
//word_stack.push(w[word_cnt].value);
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X();
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sent_id = sy_num;
-
-
if(op_stack.size()>0 && e == 0){
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op = op_stack.top();
-
op_stack.pop();
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s2 = word_stack.top();
-
word_stack.pop();
-
s1 = word_stack.top();
-
word_stack.pop();
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siYuan(op,s1,s2,res);
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}
-
-
//cout<<w[word_cnt].value<<endl;
-
if(strcmp(w[word_cnt].value,")")){
-
error("miss )");
-
word_cnt--;
-
}
-
word_cnt++;
-
if(strcmp(w[word_cnt].value,"do")){
-
error("miss do");
-
word_cnt--;
-
}
-
word_cnt++;
-
Y();
-
}
-
-
void X(){
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cout<<"X()"<<endl;
-
M();
-
-
if(op_stack.size() > 0 && e == 0){
-
op = op_stack.top();
-
op_stack.pop();
-
s2 = word_stack.top();
-
word_stack.pop();
-
s1 = word_stack.top();
-
word_stack.pop();
-
stringstream ss;
-
ss << op_num;
-
res = "t"+ss.str();
-
word_stack.push(res);
-
siYuan(op,s1,s2,res);
-
}
-
-
-
if(strcmp(w[word_cnt].value,">") == 0){
-
op = "<=";
-
}
-
else if(strcmp(w[word_cnt].value,">=") == 0){
-
op = "<";
-
}
-
else if(strcmp(w[word_cnt].value,"<") == 0){
-
op = ">=";
-
}
-
else if(strcmp(w[word_cnt].value,"<=") == 0){
-
op = ">";
-
}
-
else if(strcmp(w[word_cnt].value,"==") == 0){
-
op = "!=";
-
}
-
else if(strcmp(w[word_cnt].value,"!=") == 0){
-
op = "==";
-
}
-
//cout<<w.value<<" "<<w.type<<endl;
-
if(!L()){
-
error("miss relation operator");
-
word_cnt--;
-
}
-
op_stack.push(op);
-
word_cnt++;
-
//word_stack.push(w[word_cnt].value);
-
//sent_id = sy_num;
-
M();
-
}
-
//表达式
-
void M(){
-
cout<<"M()"<<endl;
-
N();
-
M1();
-
}
-
//子表达式
-
void M1(){
-
cout<<"M1()"<<endl;
-
cout<<w[word_cnt].value<<endl;
-
if(strcmp(w[word_cnt].value,";") == 0 || strcmp(w[word_cnt].value,")") == 0
-
|| L() || strcmp(w[word_cnt].value,"}") == 0 || strcmp(w[word_cnt].value,"else") == 0){
-
return;
-
}
-
else if(!O()){
-
error("miss + or -");
-
//word_cnt--;
-
}
-
else{
-
op_stack.push(w[word_cnt].value);
-
word_cnt++;
-
//word_stack.push(w[word_cnt].value);
-
op_num++;
-
//getWord();
-
//strcpy(b[b_num++].bds,new_w.value);
-
N();
-
M1();
-
-
if(op_stack.size() > 1 && e == 0){
-
op = op_stack.top();
-
op_stack.pop();
-
s2 = word_stack.top();
-
word_stack.pop();
-
s1 = word_stack.top();
-
word_stack.pop();
-
stringstream ss;
-
ss << op_num;
-
res = "t"+ss.str();
-
word_stack.push(res);
-
siYuan(op,s1,s2,res);
-
}
-
-
}
-
}
-
-
//项 ,消除左递归
-
void N(){
-
cout<<"N()"<<endl;
-
Z();
-
N1();
-
}
-
void N1(){
-
cout<<"N1()"<<endl;
-
cout<<w[word_cnt].value<<endl;
-
//后根符号集,关系运算符 ; )
-
if(strcmp(w[word_cnt].value,";") == 0 || strcmp(w[word_cnt].value,")") == 0
-
|| strcmp(w[word_cnt].value,"}") == 0 || strcmp(w[word_cnt].value,"else") == 0 || L() || O()){
-
return;
-
}
-
else if(!Q()){
-
error("miss * or /");
-
//分号出错转到语句
-
//word_cnt--;
-
}
-
//word_cnt++;
-
else{
-
op_num++;
-
op_stack.push(w[word_cnt].value);
-
word_cnt++;
-
//word_stack.push(w[word_cnt].value);
-
Z();
-
N1();
-
-
if(op_stack.size() > 1 && e == 0){
-
op = op_stack.top();
-
op_stack.pop();
-
s2 = word_stack.top();
-
word_stack.pop();
-
s1 = word_stack.top();
-
word_stack.pop();
-
stringstream ss;
-
ss << op_num;
-
res = "t"+ss.str();
-
word_stack.push(res);
-
siYuan(op,s1,s2,res);
-
}
-
-
}
-
}
-
//因子
-
void Z(){
-
//cout<<w.value<<" "<<w.type<<endl;
-
//非数字或标识符
-
cout<<"Z()"<<endl;
-
if(w[word_cnt].type!=1 && w[word_cnt].type!=2 &&strcmp(w[word_cnt].value,"(")){
-
error("expression has a error");
-
return;
-
}
-
//标识符
-
if(w[word_cnt].type == 1||w[word_cnt].type == 2){
-
if(w[word_cnt].type == 2){
-
is_say(w[word_cnt].value);
-
}
-
word_stack.push(w[word_cnt].value);
-
word_cnt++;
-
//equ[equ_num++] = w.value;
-
return;
-
}
-
else if(strcmp(w[word_cnt].value,"(") == 0){
-
word_cnt++;
-
//word_stack.push(w[word_cnt].value);
-
M();
-
if(e == 0){
-
op = op_stack.top();
-
op_stack.pop();
-
s2 = word_stack.top();
-
word_stack.pop();
-
s1 = word_stack.top();
-
word_stack.pop();
-
stringstream ss;
-
ss << op_num;
-
res = "t"+ss.str();
-
word_stack.push(res);
-
siYuan(op,s1,s2,res);
-
}
-
-
if(strcmp(w[word_cnt].value,")") == 0){
-
word_cnt++;
-
return;
-
}
-
else{
-
error("miss )");
-
}
-
}
-
return;
-
}
-
-
//语句1
-
void Y(){
-
cout<<"Y()"<<endl;
-
if(strcmp(w[word_cnt].value,"{") == 0){
-
word_cnt++;
-
B();
-
//cout<<w.value<<endl;
-
if(strcmp(w[word_cnt].value,"}")){
-
error("miss }");
-
}
-
word_cnt++;
-
return;
-
}
-
else{
-
H();//语句
-
return;
-
}
-
}
-
-
//关系运算符
-
int L(){
-
if(((w[word_cnt].type > 22 && w[word_cnt].type <= 26) || w[word_cnt].type == 37)){
-
return 1;
-
}
-
return 0;
-
}
-
-
//加法运算符
-
int O(){
-
if(w[word_cnt].type == 18 || w[word_cnt].type == 19){
-
return 1;
-
}
-
return 0;
-
}
-
//乘法运算符
-
int Q(){
-
if(w[word_cnt].type == 20 || w[word_cnt].type == 21){
-
return 1;
-
}
-
return 0;
-
}
-
-
int main(){
-
fin = fopen("compiler.txt","r");
-
getWord();
-
S();
-
if(e==0)
-
{
-
printFour();
-
}
-
else
-
{
-
cout<<"\nSorry,can not generate siYuan."<<endl;
-
}
-
return 0;
-
}
-
/*
-
-
*/
文章来源: fantianzuo.blog.csdn.net，作者：兔老大RabbitMQ，版权归原作者所有，如需转载，请联系作者。
原文链接：fantianzuo.blog.csdn.net/article/details/103976954
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