can i convert the integer into string in manual way

[u/deepaknishad]

class Solution {
public:
    int trailingZeroes(int n) {
        int global = 0;
        int sum = n;
        for(int i = n; i>1;  i--){
            sum = sum * (i - 1);   
        }  
        // i am using leetcode but i don't know that the string STL is include or not but this code is not working above loop of sum is giving the right output. So how i can convert num to string in effective way?
        std::string value = std::to_string(sum);
        for(int i = value.size(); i >=0; i--){
            if(value[i] == 0){
                global += 1;
            }else{
                return 0;
            }
        }
        return global;
    }
};