#include <stdio.h> // Include the standard input-output header
// Function to calculate factorial
int factorial(int n) {
int i, p = 1; // Initialize p to 1, which will hold the factorial value
// Loop from n down to 2
for (i = n; i > 1; i--) {
p *= i; // Multiply p by i at each step
}
return p; // Return the calculated factorial
}
int main() {
int a, result; // Declare variables for input number and the result
// Ask the user to input a number
printf("Enter an integer number: ");
scanf("%d", &a);
// Calculate factorial by calling the factorial function
result = factorial(a);
// Display the result
printf("The factorial of %d is %d.\n", a, result);
return 0; // Return 0 to indicate successful execution
}
Explanation:
Function Declaration (
factorial): Thefactorialfunction takes an integernas an argument and calculates its factorial using aforloop. It multiplies the variablepwith each number starting fromndown to2and returns the result.Main Function:
- It asks the user for an integer input.
- The factorial is calculated using the
factorialfunction. - The result is printed to the screen.
Sample Input/Output:
Input:
Output:
