位操作－leetcode-405. Convert a Number to Hexadecimal

原题链接：Convert a Number to Hexadecimal

比较简单，代码如下：

class Solution {public:    string toHex(int num) {        vector<string>ivec={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};        if(num==0)return "0";        string res;        int count=0;        while(num&&count<8){            res=ivec[num&15]+res;            num=num>>4;            count++;        }        return res;    }};