168. Excel Sheet Column Title

Problem

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

Solution

class Solution {
public:
string convertToTitle(int n) {
if(n == 0)
return "";
string ret = "";
while(n)
{
ret+=(--n)%26+'A';
n/=26;
}

reverse(ret.begin(),ret.end());

return ret;

}
};