C++实现字典树的增删查写前缀打印
【摘要】
C++实现字典树的增删查写前缀打印
//
// Created by jal on 19-3-9.
//
#include <bits/stdc++.h>
using namespace s...
C++实现字典树的增删查写前缀打印
//
// Created by jal on 19-3-9.
//
#include <bits/stdc++.h>
using namespace std;
const int SIZE = 26;
struct Node{
int sum;
bool isEnd;
char val;
vector<Node*>son;
Node(char val):
sum(0),isEnd(false),val(val){
son.resize(SIZE);
for(auto& node : son){
node = NULL;
}
}
};
struct Trie{//字典树,实现单词的增删查写
Node* root;
Trie(){
root = new Node('a');
}
/*
* 往字典树中插入字符串
*/
void insert(string s){
if(s.size() <= 0 || s == "")return;
Node* node = root;
for(auto& c: s){
int p = c - 'a';
if(NULL == node->son[p]){
node->son[p] = new Node(c);
}
node->son[p]->sum++;
node = node->son[p];
}
node->isEnd = true;
}
/*
* 查找字符串是否在字典树中
*/
bool search(string s){
if(s.size() <= 0 || s == "")return false;
Node* node = root;
for(auto& c: s){
int p = c - 'a';
if(NULL == node->son[p]){
return false;
}
node = node->son[p];
}
return node->isEnd;
}
/*
* 统计以s为前缀的字符串的个数
*/
int countPrefix(string s){
if(s.size() <= 0 || s == "")return 0;
Node* node = root;
for(auto& c: s){
int p = c - 'a';
if(NULL == node->son[p]){
return 0;
}
node = node->son[p];
}
return node->sum;
}
/*
* 从字典树中删除s,成功返回true,失败返回false
*/
void deleteString(string s){
if(s.size() <= 0 || s == "")return;
Node* node = root;
for(auto& c: s){
int p = c - 'a';
if(NULL == node->son[p]){
return;
}
if(node->son[p]->sum-- <= 1){
node->son[p] = NULL;
return;
}
node = node->son[p];
}
node->isEnd = false;
}
/*
* 查找以s为前缀的字符串在字典中的节点指针
*/
Node* getPrefixNode(string s){
if(s.size() <= 0 || s == "")return NULL;
Node* node = root;
for(auto& c: s){
int p = c - 'a';
if(NULL == node->son[p]){
return NULL;
}
node = node->son[p];
}
return node;
}
/*
* 中序遍历打印以s为前缀,指针为root的字典树
*/
void preTraverse(string s, Node* root){
if(root->isEnd){
cout << s << endl;
}
for (int i = 0; i < SIZE; ++i) {
if(root->son[i] != NULL){
preTraverse(s+root->son[i]->val, root->son[i]);
}
}
return;
}
/*
* 打印以s为前缀的字符串
*/
void printStringByPrefix(string s){
if(s.size() <= 0 || s == "")return;
if(countPrefix(s) <= 0)return;
if(search(s))cout << s << endl;
Node* node = getPrefixNode(s);
preTraverse(s,node);
}
};
int main(){
Trie trie;
trie.insert("jal");
trie.insert("jiailing");
trie.insert("jiailingx");
trie.insert("jisuanji");
cout << trie.search("jiailing") << endl;
cout << trie.countPrefix("iai") << endl;
cout << trie.countPrefix("ji") << endl;
cout << trie.countPrefix("j") << endl;
cout << trie.search("jal") << endl;
trie.deleteString("jal");
cout << trie.search("jal") << endl;
cout << trie.countPrefix("j") << endl;
trie.printStringByPrefix("j");
}
文章来源: blog.csdn.net,作者:爱玲姐姐,版权归原作者所有,如需转载,请联系作者。
原文链接:blog.csdn.net/jal517486222/article/details/88365106
【版权声明】本文为华为云社区用户转载文章,如果您发现本社区中有涉嫌抄袭的内容,欢迎发送邮件进行举报,并提供相关证据,一经查实,本社区将立刻删除涉嫌侵权内容,举报邮箱:
cloudbbs@huaweicloud.com
- 点赞
- 收藏
- 关注作者
评论(0)