LeetCode:504. Base 7

Given an integer, return its base 7 string representation.

Example 1:

Input: 100Output: "202"

Example 2:

Input: -7Output: "-10"

Note: The input will be in range of [-1e7, 1e7].

将十进制换成七进制。

AC:

class Solution {public:    string convertToBase7(int num) {      int x = abs(num); string res;      do res = to_string(x%7)+res; while(x/=7);      return (num>=0? "" : "-") + res;    }};