题解 | #进制转换#

import java.util.*;


public class Solution {
    /**
     * 进制转换------除N取余法
     * @param M int整型 给定整数
     * @param N int整型 转换到的进制
     * @return string字符串
     */
    public String solve (int M, int N) {
        // write code here
        char[] cha = new char[]{'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
//         String str = "0123456789ABCDEF";
        boolean flag = true;
        int shang = M;
        int yushu = 0;
        if(M<0){//正负数处理
            flag = false;
            shang = -1*M;
        }
        StringBuffer stringBuffer = new StringBuffer();
        while(shang != 0){
            yushu = shang % N;//求余
            stringBuffer.append(cha[yushu]);
//             stringBuffer.append(str.charAt(yushu));
            shang = shang / N;//求商
        }
        
        if(!flag){//正负数处理
            stringBuffer.append('-');
        }
        
        return stringBuffer.reverse().toString();
    }
}