Given an integer, return its base 7 string representation.
Example 1:
Input: 100 Output: "202"
Example 2:
Input: -7 Output: "-10"
Note: The input will be in range of [-1e7, 1e7].
public class Solution {public string ConvertToBase7(int num) {if (num == 0) {return "0";}int number = Math.Abs(num);string str = "";while (number > 0) {int n = number % 7;str = n.ToString() + str;number /= 7;}if (num < 0) {str = "-" + str;}return str;}}
原文：http://www.cnblogs.com/xiejunzhao/p/464fc1a6b2c44d3e0fb58a82290ad9e9.html