C Exercises: Find the factorial of a given number

Last update on March 19 2025 12:40:36 (UTC/GMT +8 hours)

12. Factorial Using Pointers

Write a program in C to find the factorial of a given number using pointers.

Visual Presentation:

Sample Solution:

C Code:

#include <stdio.h>

// Function prototype to find factorial of a number using pointers
void findFact(int, int*);

int main() {
    int fact; // Variable to store factorial
    int num1; // Variable to store user input

    printf("\n\n Pointer : Find the factorial of a given number :\n"); 
    printf("------------------------------------------------------\n");	

    // Input a number from the user
    printf(" Input a number : ");
    scanf("%d", &num1);		

    // Call the function to calculate factorial passing the address of 'fact'
    findFact(num1, &fact);

    // Display the factorial of the given number
    printf(" The Factorial of %d is : %d \n\n", num1, fact);

    return 0;
}

// Function definition to find factorial using pointers
void findFact(int n, int *f) {
    int i;
    *f = 1; // Initialize the factorial to 1

    // Loop to calculate factorial of the given number
    for (i = 1; i <= n; i++) {
        *f = *f * i; // Calculate factorial by multiplying *f with i
    }
}
	   

Sample Output:

 Pointer : Find the factorial of a given number :                                                             
------------------------------------------------------                                                        
 Input a number : 5                                                                                           
 The Factorial of 5 is : 120

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C program to compute the factorial of a number using recursion and pointer parameters.
• Write a C program to calculate the factorial iteratively using a pointer to update the result.
• Write a C program to compute the factorial of a number using dynamic memory allocation and pointers.
• Write a C program to compute the factorial using a function that returns a pointer to the result.

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