Skip to content
GATETECH
Official PYQ · 2015Set 3 · Q26Programming in CNAT1 mark

GATE CS 2015 Set 3 Q26 — Programming in C

Explain with AI

Consider the following C program

#include<stdio.h>  
int main()  {
    static int a[] = {10, 20, 30, 40, 50};
    static int *p[] = {a, a+3, a+4, a+1, a+2};
    int **ptr = p;
    ptr++;
    printf("%d%d", ptr-p, **ptr);  
    
}

The output of the program is _______.

View worked solution

Answer: 140

Let's trace the execution of the program step-by-step:

  1. Array a: An array of 5 integers: a = {10, 20, 30, 40, 50}.
  2. Pointer Array p: An array of 5 pointers initialized as:
    • p[0] = a (points to a[0], value 10)
    • p[1] = a + 3 (points to a[3], value 40)
    • p[2] = a + 4 (points to a[4], value 50)
    • p[3] = a + 1 (points to a[1], value 20)
    • p[4] = a + 2 (points to a[2], value 30)
  3. Pointer ptr:
    • Initially, ptr = p (points to p[0]).
    • After ptr++, ptr points to p[1].
  4. Evaluating the printf arguments:
    • ptr - p: Pointer subtraction yields the number of elements between them. Since ptr points to p[1] and p points to p[0], ptr - p = 1.
    • **ptr: Dereferencing ptr once gives *ptr = p[1] = a + 3. Dereferencing it again gives *(a + 3) = a[3] = 40.

The printf statement prints ptr - p and **ptr consecutively without any spaces: 1 and 40, resulting in 140.

Free practice · Your answers on this page are not saved.

Published
Report a correction
Keep exploringMore Programming in C questions