Leetcode Excel Sheet Column Title problem solution

import string
class Solution(object):
    def convertToTitle(self, n):
        alph = string.ascii_uppercase
        res = ""
        while n:
            n, r = (n-1)//26, (n-1)%26
            res += alph[r]
        return (res[::-1])

class Solution {
    public String convertToTitle(int n) {

        StringBuilder result = new StringBuilder();
        while(n>0){
            n--;
         
            char toAdd = (char)((n % 26) + 65);
            result.insert(0,toAdd);
            
            n = n/26;
            
        }
        return result.toString();
        
    }
}

string convertToTitle(int n) {
		string res = "";
		while(n>0)
		{
			int i =(n-1)%26; 
			res = (char)('A'+i) + res;
			n=(n-1)/26;
		}
		return res;
	}

char *convertToTitle(int n) {
    char *s;
    int fac = 26, char_size = 0, num = n, i = 1;
    while(num > 0) {
        num = (num - 1) / 26;
        char_size++;
    }
    s=(char*)malloc(char_size*sizeof(char));
    while(n>0){
        n--;
        *(s+char_size-i) = (char)(n%fac +'A') + *s;
        n/=fac;
        i++;
    }
    return s;
}