Fundamentals of Computer Programming - Old Questions

8. What is recursion? Write a program to find the factorial of given number using recursion. [2+4]

OR

What is pointer? Write a program to sort 'n' numbers in ascending order using dynamic memory. [2+4]

A function that calls itself is known as a recursive function. And, this technique is known as recursion.

Program  to find the factorial of given number using recursion:

#include<stdio.h>

int fact(int);

int main()

{

    int x,n;

    printf(" Enter the Number to Find Factorial :");

    scanf("%d",&n);

    x=fact(n);

    printf(" Factorial of %d is %d",n,x);

    return 0;

}

int fact(int n)

{

    if(n==0)

        return(1);

    return(n*fact(n-1));

}

____________________________

OR Part:

A pointer is a variable whose value is the address of another variable, i.e., direct address of the memory location.

program to sort 'n' numbers in ascending order using dynamic memory:

#include<stdio.h>

#include<stdlib.h>

int main()

{

      int *a,n,i,j,t;

      printf("How many numbers you want to be sorted: ");

      scanf("%d",&n);

      a=(int *)malloc(n *sizeof(int));

      printf("\\nEnter %d Numbers: \\n\\n",n);

      for(i=0;i<=n-1;i++)

      {

            scanf("%d", (a+i));

      }

      for(i=0;i<n;i++)

      {

            for(j=0;j<=i;j++)

            {

                  if(*(a+i)<*(a+j))

                  {

                        t=*(a+i);

                        *(a+i)=*(a+j);

                        *(a+j)=t;

                  }

            }

      }

      printf("\\nAfter Sorting in Ascending Order: \\n");

      for(i=0;i<n;i++)

      printf("\\n%d",*(a+i));

      return 0;

}