Leetcode33: Excel Sheet Column Title

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

For example:

    1 -> A
    2 -> B
    3 -> C
    ...
    26 -> Z
    27 -> AA
    28 -> AB 

Credits:

Special thanks to @ifanchu for adding this problem and creating all test cases.

和上一道题是相反的，实现起来也比较容易。

class Solution {
public:
    string convertToTitle(int n) {
        string str = "";
        char s ;
        while(n)
        {
            s = ((n-1)%26 + 'A');
            str = s + str;
            n = (n-1)/26;
        }
        return str;
    }
};