C Program to Find the Sum of Natural Numbers using Recursion

Code:

#include <stdio.h>
int Sum(int x);
int Sum(int x)
{
    if (x != 0)
        return x + Sum(x - 1);
    else
        return x;
}
int main()
{
    int number;
    printf("Enter a number: ");
    scanf("%d", &number);
    printf("Sum of natural numbers is %d\n", Sum(number));
    return 0;
}

Output:

Enter a number: 5
Sum of natural numbers is 15

C Program to Find Factorial of a Number Using Recursion

Code:

#include <stdio.h>
long int Fact(int n);
long int Fact(int n)
{
    if (n >= 1)
        return n * Fact(n - 1);
    else
        return 1;
}
int main()
{
    int n;
    printf("Enter a number: ");
    scanf("%d", &n);
    printf("Factorial is %ld\n", Fact(n));
    return 0;
}

Output:

Enter a number: 5
Factorial is 120

C Program to Find G.C.D Using Recursion

Code:

#include <stdio.h>
int GCD(int number1, int number2);
int GCD(int number1, int number2)
{
    if (number2 != 0)
        return GCD(number2, number1 % number2);
    else
        return number1;
}
int main()
{
    int number1, number2;
    printf("Enter first number: ");
    scanf("%d", &number1);
    printf("Enter second number: ");
    scanf("%d", &number2);
    printf("G.C.D is %d\n", GCD(number1, number2));
    return 0;
}

Output:

Enter first number: 8
Enter second number: 4
G.C.D is 4

C program to Reverse a Sentence Using Recursion

Code:

#include <stdio.h>
void Rev();
void Rev()
{
    char ch;
    scanf("%c", &ch);
    if (ch != '\n')
    {
        Rev();
        printf("%c", ch);
    }
}
int main()
{
    printf("Enter sentence: ");
    Rev();
    printf("\n");
    return 0;
}

Output:

Enter sentence: Welcome To Codedec
cededoC oT emocleW

C program to calculate the power using recursion

Code:

#include <stdio.h>
int power(int number1, int number2);
int power(int A, int n)
{
    if (n != 0)
        return (A * power(A, n - 1));
    else
        return 1;
}
int main()
{
    int A, n, value;
    printf("Enter a number: ");
    scanf("%d", &A);
    printf("Enter power value: ");
    scanf("%d", &n);
    value = power(A, n);
    printf("Desired value is %d\n", value);
    return 0;
}

Output:

Enter a number: 5
Enter power value: 3
Desired value is 125