#include <stdio.h>
// Function to calculate the factorial of a number
int factorial(int n) {
if (n == 0 || n == 1) {
return 1;
} else {
return n * factorial(n - 1);
}
}
// Main function
int main() {
// Declare variables
int num;
// Prompt user for input
printf("Enter a non-negative integer: ");
// Read input from user
scanf("%d", &num);
// Check if the input is non-negative
if (num < 0) {
printf("Error: Please enter a non-negative integer.\n");
} else {
// Calculate and print the factorial
printf("The factorial of %d is: %d\n", num, factorial(num));
}
// Return 0 to indicate successful completion
return 0;
}