[LeetCode]405. Convert a Number to Hexadecimal

题目描述

思路

位运算，每次获取4位，转化为对应的16进制数
因为题目说不会超过32位int并且负数用补码，那可以加入位置计数器，32位二进制表示成十六进制是8位

代码

#include <iostream>#include <string>using namespace std;class Solution {public:    string toHex(int num) {        if (num == 0)            return "0";        string hex = "0123456789abcdef", res = "";        int count = 0;        while (num && count < 8) {            res = hex[num & 0xf] + res;            num >>= 4;            ++count;        }        return res;    }};int main() {    Solution s;    cout << s.toHex(-1) << endl;    system("pause");    return 0;}