# Factorial of a number

Sun Feb 06 2022 02:48:25 GMT+0000 (UTC)

```// ITERATIVE CODE : Time Complexity : Θ(n), Auxiliary Space : Θ(1)

import java.io.*;
import java.util.*;

public class Main {

static int fact(int n)
{
int res = 1;

for(int i=2; i<=n; i++)
{
res = res * i;
}
return res;
}

public static void main (String[] args) {

int number = 5;

System.out.println(fact(number));

}
}

// RECURSIVE CODE : Time Complexity : Θ(n), Auxiliary Space : Θ(n)

import java.io.*;
import java.util.*;

public class Main {

static int fact(int n)
{
if(n==0)
return 1;

return n * fact(n-1);
}

public static void main (String[] args) {

int number = 5;

System.out.println(fact(number));

}
}```
content_copyCOPY

Factorial Of Number Given a positive integer N. The task is to find factorial of N. Example 1: Input: N = 4 Output: 24 Explanation: 4! = 4 * 3 * 2 * 1 = 24 Example 2: Input: N = 13 Output: 6227020800 Explanation: 13! = 13 * 12 * .. * 1 = 6227020800 Your Task: You don't need to read input or print anything. Your task is to complete the function factorial() that takes N as parameter and returns factorial of N. Expected Time Complexity: O(N) Expected Auxilliary Space: O(1) Constraints: 0 <= N <= 18

https://practice.geeksforgeeks.org/tracks/DSASP-Mathematics/?batchId=190&tab=2