C Interview Questions & Answers || Experienced Level || Set - II

Question: What is the program to print the factorial of a number using recursion?

Answer: The C program to find the factorial of a given number using recursion is as follows:

// C program to find factorial // of a given number

#include <stdio.h> // Function to find factorial of // a given number

unsigned int factorial(unsigned int n)

{

    if (n == 0)

        return 1;

    return n * factorial(n - 1);

}

// Driver code

int main()

{

    int num = 5;

    printf("Factorial of %d is %d", num, factorial(num));

    return 0;

}

// Output: Factorial of 5 is 120

Question: What is the use of an extern storage specifier?

Answer: The extern storage specifier, which is short for external, is used to increase the visibility of C functions and variables. It is used by one file to access variables from another file.

Question: Write a program to check an Armstrong number.

Answer: The C program to determine whether the given number is an Armstrong number or not is as follows:

// C program to determine whether // the given number is Armstrong // or not

#include <stdio.h> // Driver code

int main()

{

    int n;

    printf("Enter Number \n");

    scanf("%d", &n);

    int var = n;

    int sum = 0;

    // Loop to calculate the order of // the given number

    while (n > 0)

    {

        int rem = n % 10;

        sum = (sum) + (rem * rem * rem);

        n = n / 10;

    }

    // If the order of the number will be // equal to the number then it is // Armstrong number.

    if (var == sum)

    {

        printf("%d is an Armstrong number \n", var);

    }

    else

    {

        printf("%d is not an Armstrong number", var);

    }

    return 0;

}

// Output example: Enter Number 0 is an Armstrong number

Question: Write a program to reverse a given number.

Answer: The C program to reverse digits of a number is as follows:

// C program to reverse digits // of a number

#include <stdio.h> // Driver code

int main()

{

    int n, rev = 0;

    printf("Enter Number to be reversed : ");

    scanf("%d", &n);

    // r will store the remainder while we // reverse the digit and store it in rev

    int r = 0;

    while (n != 0)

    {

        r = n % 10;

        rev = rev * 10 + r;

        n /= 10;

    }

    printf("Number After reversing digits is: %d", rev);

    return 0;

}

// Output example: Enter Number to be reversed : 123 Number After reversing digits is: 321

…till next post, bye-bye & take care.