Given a positive integer, return its corresponding column title as appear in an Excel sheet.
1 -> A
2 -> B
3 -> C
...
26 -> Z
27 -> AA
28 -> AB
class Solution {
public:
string convertToTitle(int n) {
string res;
char temp;
while(n){
n -= 1;
int bit = n%26;
temp = bit + 'A';
res = temp + res;
n /= 26;
}
return res;
}
};