NIELIT M3-R4: Q.No. 9(b) January 2013

M3-R4: January 2013 (O-Level)

Q. 9(b):
Write a ‘C’ program to find out a factorial of a given number?

Ans:

Method 1: Finding factorial using loop: 

#include <stdio.h>
#include <conio.h>

void main(){
    int num, i;
    long fact = 1;
    printf("\nEnter an integer: ");
    scanf("%d", &num);
    for(i=num; i>0; i--){
        fact = fact * i;
    }
    printf("\n%d! = %ld", num, fact); 
    getch();
}


Method 2: Finding factorial using recursive function: 

#include <stdio.h>
#include <conio.h>

long fact(int);

void main(){
    int num;
    long f;
    printf("\nEnter an integer: ");
    scanf("%d", &num);
    f = fact(num);
    printf("\n%d! = %ld", num, f); 
    getch();
}


long fact(int n){
    if(n <= 0)
        return 1;
    return n * fact(n-1);
}