计算糖果_进制转换

计算糖果

计算糖果

// 要求ABC都为整数
// 注意多了一个约束条件，即四个式子解3个未知数，所以还要确定满不满足A+B==n3
import java.util.Scanner;
public class Main {	
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		int n1 = in.nextInt();
		int n2 = in.nextInt();
		int n3 = in.nextInt();
		int n4 = in.nextInt();
		int A = (n1+n3)/2;
		int B = (n2+n4)/2;
		int C = B-n2;
        //这里的取余操作,保证用例满足条件!
        // 例如: 0 -1 3 5 NO!
        // A+B == n3 保证解是正确符号题意的!
        // 11 -7 0 error 
		if((n1+n3)%2==0&&(n2+n4)%2==0&&(A+B==n3)){
			System.out.println(A+" "+B+" "+C);
		}else{
			System.out.println("No");
		}
	}
}
//常规方法!
import java.util.Scanner;
public class Main {	
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		int n1 = in.nextInt();// A - B
		int n2 = in.nextInt();// B - C 
		int n3 = in.nextInt();// A + B 
		int n4 = in.nextInt();// B + C
		int A = (n1+n3)/2;// A
		int B1 = (n2+n4)/2;// B1
        int B2 = (n3-n1)/2;// B2
		int C =  (n4-n2)/2;// C 
		if(B1==B2){//B1 == B2 说明解是正确的!
			System.out.println(A+" "+B1+" "+C);
		}else{
			System.out.println("No");
		}
	}
}

进制转换

进制转换

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String result = "";//结果表
        String table = "0123456789ABCDEF";//进制表
        while(sc.hasNext()){
            int M = sc.nextInt();
            int N = sc.nextInt();
            if(M==0){
                result += "0";
            }
            while(M!=0){
                if(M<0){
                    M=-M;//负数!
                   System.out.print("-");
                }
                //字符串拼接, 后面的结果拼接在前!
                result = table.charAt(M%N) + result;
                M/=N;
            }
            System.out.println(result);
        }
    }
}
//代码优化!
//str1+str2+...strn 会产生n-1个临时对象，那么避免大量无效对象的创建，所以提倡用stringbuffer.append()避免产生无效临时变量
import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        StringBuilder result = new StringBuilder();//结果表
        String table = "0123456789ABCDEF";//进制表
        while(sc.hasNext()){
            int M = sc.nextInt();
            int N = sc.nextInt();
            if(M==0){
               result.append(0);
            }
            while(M!=0){
                if(M<0){
                    M=-M;//负数!
                   System.out.print("-");
                }
                result.append(table.charAt(M%N));
                M/=N;
            }
            result.reverse();//逆置!
            System.out.println(result);
        }
    }
}