Array Reversal - HackerRank Solution

Given an array, of size n, reverse it.

Example: If array, arr = [1,2,3,4,5], after reversing it, the array should be, arr = [5,4,3,2,1].

Input Format

The first line contains an integer, n, denoting the size of the array. The next line contains n space-separated integers denoting the elements of the array.

Constraints

1≤n≤1000

1≤arr_i≤1000, where arr_i is the i^th element of the array.

Output Format

The output is handled by the code given in the editor, which would print the array.

Sample Input 0

6

16 13 7 2 1 12 

Sample Output 0

12 1 2 7 13 16 

Explanation 0

Given array, arr = [16,13,7,2,1,12] . After reversing the array, arr =[12,1,2,7,13,16] 

Sample Input 1

7

1 13 15 20 12 13 2

 

Sample Output 1

2 13 12 20 15 13 1

 

Sample Input 2

8

15 5 16 15 17 11 5 11

 

Sample Output 2

11 5 11 17 15 16 5 15 

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Array Reversal - HackerRank Solution

#include <stdio.h>
#include <stdlib.h>
int main()
{
    int num, *arr, i;
    scanf("%d", &num);
    arr = (int*) malloc(num * sizeof(int));
    for(i = 0; i < num; i++)
        scanf("%d", arr + i);
    void swap(int* a, int* b) { 
        int temp = *a; 
        *a = *b; 
        *b = temp; 
    }  
    int *pointer1 = arr, *pointer2 = arr + num - 1; 
    while (pointer1 < pointer2) { 
        swap(pointer1, pointer2); 
        pointer1++; 
        pointer2--; 
    } 
    /* Write the logic to reverse the array. */
    for(i = 0; i < num; i++)
        printf("%d ", *(arr + i));
    return 0;
}