Leetcode 405. 数字转换为十六进制数 class Solution { public: string toHex(int num) { if (num == 0) return "0"; string s = "0123456789abcdef"; long long n = num < 0 ? num + (1ll << 32) : num; string str; while (n) { str = s[n % 16] + str; n /= 16; } return str; } };