HackerEarth Small Factorials problem solution

In this HackerEarth Small Factorials problem solution, You are asked to calculate factorials of some small positive integers.

HackerEarth Small Factorials problem solution.

`#include<bits/stdc++.h> #define ll long long#define ull unsigned long long#define repA(i,a,n) for(int i=a;i<n;i++)#define repD(i,a,n) for(int i=n-1;i>=a;i--)#define fast ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0) using namespace std;#define MAX 500int res[MAX];int multiply(int x, int res[], int res_size);void factorial(int n){   res[0] = 1;   int res_size = 1;    for (int x=2; x<=n; x++)   {       res_size = multiply(x, res, res_size);   }      for (int i=res_size-1; i>=0; i--)       cout << res[i];} int multiply(int x, int res[], int res_size){   int carry = 0;    for (int i=0; i<res_size; i++)   {       int prod = res[i] * x + carry;       res[i] = prod % 10;         carry  = prod/10;       }    while (carry)   {       res[res_size] = carry%10;       carry = carry/10;       res_size++;   }   return res_size;} int main(){  fast;  int t; cin>>t; while(t--){          int n;     cin>>n;     factorial(n);     cout<<"\n"; }}`