LargeFactorial.cpp

#include <bits/stdc++.h>

using namespace std;


void multiply(vector<int> &a, int no, int &size) {
   
   int carry = 0;

   for(int i=0; i <size; i++) {
   	int product = a[i] * no + carry;
   	a[i] = product % 10;

   	carry = product / 10;
   }
   while(carry) {
   	a[size] = carry % 10; 
   	carry = carry / 10;
   	size = size + 1;
   }
}

void bigFactorial(int n) {
	vector<int> a(1000,0);

	a[0] = 1;

	int size = 1;

	for(int i = 2; i <=n;i++) {

		 multiply(a,i,size);
	}

	for(int i = size- 1; i >=0; i--) {
		cout<<a[i];
	}
	cout<<endl;
}

int main() {
     #ifndef ONLINE_JUDGE
    // for getting input from input.txt
    freopen("input.txt", "r", stdin);
    // for writing output to output.txt
    freopen("output.txt", "w", stdout);
    #endif
    
    int n;

    cin>>n;

    bigFactorial(n);


	return 0;
}