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Ques:-12) Write a program to find the factorial value of any number entered through the keyboard.
#include<stdio.h>
#include<conio.h>
void main()
{
int num,fact=1;
clrscr();
printf("\nenter any number:");
scanf("%d",&num);
for(num;num>0;num--)
{
fact=fact*num;
}
printf("factorial is %d",fact);
getch();
}
Out Put
Enter any number 5
factorial is 120
Below is a simple C program that calculates the factorial of a number entered by the user.
#include <stdio.h>
// Function to calculate factorial
long long int factorial(int n) {
if (n == 0 || n == 1) {
return 1;
} else {
return n * factorial(n - 1);
}
}
int main() {
int number;
long long int result;
// Prompt user for input
printf("Enter a number to find its factorial: ");
scanf("%d", &number);
// Check for negative input
if (number < 0) {
printf("Factorial of a negative number doesn't exist.\n");
} else {
// Calculate factorial
result = factorial(number);
// Display the result
printf("Factorial of %d is %lld\n", number, result);
}
return 0;
}
Explanation
- factorial Function: This function recursively calculates the factorial of a given number. The base case is when
nis 0 or 1, where the factorial is 1. For other values, it calls itself withn-1and multiplies the result byn. - main Function:
- Prompts the user to enter a number.
- Reads the input number.
- Checks if the entered number is negative, as factorials for negative numbers are undefined.
- Calls the
factorialfunction to compute the factorial of the number if it is non-negative. - Prints the result.
Sample Output
Here are a few sample outputs when the program is executed:
Example 1:
Enter a number to find its factorial: 5
Factorial of 5 is 120
Example 2:
Enter a number to find its factorial: 0
Factorial of 0 is 1
Example 3:
Enter a number to find its factorial: -3
Factorial of a negative number doesn't exist.
This program handles both positive and negative inputs appropriately and calculates the factorial using a recursive function. For very large numbers, you might need to consider using a different method to avoid stack overflow due to recursion depth limits or switch to an iterative approach.
