题解 | #进制转换#

import java.util.*;
public class Solution {
    public String solve (int M, int N) {
        Stack stack=new Stack();
        String res=""; //存放结果
        if(M<0){
            M=M*(-1);
            res="-";
        }
        int yu=0;int shang=M;
        if(N<10){
            while(shang>N){
                yu=shang%N;
                shang=shang/N;
                stack.push(yu);
            }
        }
        else if(N>10){
            while(shang>N){
                yu=shang%N;
                shang=shang/N;
                if(yu>=10){
                    int carry=yu-10;
                    char tmp='A';
                    for(int i=0;i<carry;i++){
                        tmp++;
                    }
                    stack.push(tmp);
                }
                else{
                    stack.push(yu);
                }
            }
        }
        else{
            return String.valueOf(M);
        }
        stack.push(shang);
        while(!stack.isEmpty()){
            res=res+stack.pop();
        }
        return res;
    }
}