Array Reversal in C Hackerrank Solution

Introduction

In this article, we will delve into the topic of array reversal in C and explore the solution to a popular problem on Hackerrank.

Reversing an array is a common programming task that involves changing the order of elements in an array. We will discuss the approach to solving this problem and provide a step-by-step guide for implementing the solution in C.

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Whether you are a beginner or an experienced programmer, this article will help you understand the concept of array reversal and enhance your coding skills.

What is Array Reversal?

Before we proceed further, let’s first understand what array reversal means. Array reversal involves rearranging the elements of an array in reverse order.

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The first element becomes the last, the second element becomes the second-to-last, and so on. This process effectively flips the array, changing the order of elements to their reverse positions.

Array Reversal in C Hackerrank Solution

Now, let’s explore the array reversal solution in C for the Hackerrank problem. The problem statement asks us to reverse the given array and print the reversed array as the output.

We can achieve this using different techniques. In the previous example, we used a swapping technique. Let’s now look at another approach using pointers.

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Here is the step-by-step solution for array reversal in C using pointers:

Step 1: Input the Array

To begin, we need to input the array elements from the user. The number of elements and their values will vary depending on the problem.

We can use a loop to iterate through the array and prompt the user to enter each element.

#include<stdio.h>

int main() {
   int n, i;
   printf("Enter the number of elements in the array: ");
   scanf("%d", &n);
   int arr[n];
   printf("Enter the elements of the array:\n");
   
   for(i=0; i<n; i++) {
      scanf("%d", &arr[i]);
   }
   
   // Array reversal code goes here
   
   return 0;
}

Step 2: Perform Array Reversal using Pointers

Once we have the array elements, we can proceed with reversing the array using pointers. We will use two pointers, one pointing to the first element and the other pointing to the last element.

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By swapping the elements pointed to by these pointers and moving them towards the center of the array, we can reverse the array.

// Array reversal code

int *start = arr;
int *end = arr + n - 1;

while (start < end) {
   int temp = *start;
   *start = *end;
   *end = temp;
   start++;
   end--;
}

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Step 3: Print the Reversed Array

Finally, we need to print the reversed array as the output. We can use a loop to iterate through the reversed array and display each element.

printf("Reversed array:\n");
for(i=0; i<n; i++) {
   printf("%d ", arr[i]);
}

That’s it! We have successfully reversed the array in C using pointers. The complete code snippet for array reversal in C is as follows:

#include<stdio.h>

int main() {
   int n, i;
   printf("Enter the number of elements in the array: ");
   scanf("%d", &n);
   int arr[n];
   printf("Enter the elements of the array:\n");
   
   for(i=0; i<n; i++) {
      scanf("%d", &arr[i]);
   }
   
   int *start = arr;
   int *end = arr + n - 1;

   while (start < end) {
      int temp = *start;
      *start = *end;
      *end = temp;
      start++;
      end--;
   }
   
   printf("Reversed array:\n");
   for(i=0; i<n; i++) {
      printf("%d ", arr[i]);
   }
   
   return 0;
}

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FAQs about Array Reversal in C Hackerrank Solution

Here are some frequently asked questions about array reversal in C and its solution for the Hackerrank problem:

Conclusion

In conclusion, array reversal in C is a fundamental programming concept that involves changing the order of elements in an array.

We discussed two approaches for reversing an array: one using a swapping technique and the other using pointers. Both methods are efficient and allow us to reverse the array in-place.

By understanding and practicing array reversal, you can strengthen your programming skills and tackle similar problems with confidence.