Reverse an Array In-Place

Code

#include <stdio.h>

void reverse_array(int arr[], int n) {
    // Your logic here
    int s = 0;
    int e = n - 1;

    int half;
    if(n % 2 == 0){
        
        half = (n / 2) - 1;
        
        while(s <= half){
            arr[s] += arr[e];
            arr[e] = arr[s] - arr[e];
            arr[s] -= arr[e];
            s++;
            e--;
        }
    } else {
        half = ((n-1) / 2);
        
        while(s < half){
            arr[s] += arr[e];
            arr[e] = arr[s] - arr[e];
            arr[s] -= arr[e];
            s++;
            e--;
        }
    }    
}

int main() {
    int n;
    scanf("%d", &n);

    int arr[100];
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    reverse_array(arr, n);

    for (int i = 0; i < n; i++) {
        printf("%d", arr[i]);
        if(i < n-1){
        	printf(" ");
        }
    }
    return 0;
}

Solving Approach

 

 

 

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Input

5 1 2 3 4 5

Expected Output

5 4 3 2 1