C :

#include<stdio.h>
int main()
{
	int n,a,i,s;
	s=1;
	scanf("%d",&n);
	while(n--)
	{
		scanf("%d",&a);
		for(i=1;i<=a;i++)
		{
			s=s*i;
		}
		printf("%d\n",s);
		s=1;
	}
	return 0;
}

C++ :

#include <iostream>
#include <cstring>
#include <fstream>
using namespace std;

int fact(int n)
{
	int res=1;
	for(int i=n;i>=1;i--)
	{
		res*=i;
	}
	return res;
	
}

int main()
{
	//ofstream cout;
	//ifstream cin;
	//cin.open("d.in");
	//cout.open("d.out");
	
	int testcase;
	cin>>testcase;
	while(testcase--)
	{
		int tmp;
		cin>>tmp;
		int res=fact(tmp);
		cout<<res<<endl;
		
		
	}
	
	return 0;
}

Java :

import java.util.Scanner;
class Main {
	public static void main(String[] args) {
		JiCheng test=new JiCheng();
		Scanner reader=new Scanner(System.in);
		int T=reader.nextInt();
		for(int i=0;i<T;i++){
			int first=reader.nextInt();
			System.out.println(test.add(first));
		}
	}
}
class JiCheng{
	int add(int a){
		int b=1;
		for(int i=1;i<=a;i++){
			b=b*i;
		}
		return b;
	}
}