GATE CS 2019 Set 1 — Question 63
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.NAT+2 / -0MediumPointers & Pointer ArithmeticC ProgrammingProgramming & Data StructuresArrays & Strings in C
Programming & Data Structures → C Programming → Arrays & Strings in C
Last updated
Question
Consider the following C program:The output of the above C program is ___________.
#include <stdio.h>
int main()
{
int a[] = {2, 4, 6, 8, 10};
int i, sum = 0, *b = a + 4;
for (i = 0; i < 5; i++)
sum = sum + (*b - i) - *(b - i);
printf ("%d\n", sum);
return 0;
}
Correct answer
10 to 10
Solution
The program initializes an array .
A pointer is initialized to , which points to the last element .
The loop runs for .
In each iteration, the variable
Note that
A pointer is initialized to , which points to the last element .
The loop runs for .
In each iteration, the variable
sum is updated as: sum = sum + (*b - i) - *(b - i).Note that
*b is always (dereferencing the fixed pointer ), and *(b - i) is the element at index of array (using pointer arithmetic).Iteration-wise trace:1.For :
sum = 0 + (10 - 0) - a[4] = 10 - 10 = 02.For :
sum = 0 + (10 - 1) - a[3] = 9 - 8 = 13.For :
sum = 1 + (10 - 2) - a[2] = 1 + 8 - 6 = 34.For :
sum = 3 + (10 - 3) - a[1] = 3 + 7 - 4 = 65.For :
The final value of sum = 6 + (10 - 4) - a[0] = 6 + 6 - 2 = 10sum is , which is printed by the printf statement.Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE CS question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on C Programming
2026 Set 2 Q12The set T represents various traversals over binary tree. The set S represents the order of…2026 Set 2 Q19Consider the following three ANSI-C programs, P1, P2, and P3. P1 [code] P2 [code] **P3**…2026 Set 1 Q23Let be an odd number greater than 100. Consider a binary minheap with elements stored in an…2026 Set 1 Q24Consider a hash table that is initially empty. The hash table is maintained…2026 Set 1 Q27Consider the following C statements: Which of the following options is/are correct? [figure]