Rotate Array

Priyanka

2 min read

·

Oct 9, 2026

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Approach to Solve: Reversal Algorithm

We can solve this problem efficiently using the Reversal Algorithm, which reverses parts of the array instead of creating a new array.

The main idea is to reverse the entire array first and then reverse the two individual sections to get the desired result.

Step 1: Reverse the entire array

Initially:

[1, 2, 3, 4, 5, 6, 7]

After reversing the entire array:

[7, 6, 5, 4, 3, 2, 1]

Step 2: Reverse the first k elements

Since k = 3, reverse the first three elements:

[5, 6, 7, 4, 3, 2, 1]

Step 3: Reverse the remaining elements

Reverse the elements from index k to the last index:

[5, 6, 7, 1, 2, 3, 4]

This gives us the final rotated array.

Java Code

class Solution {

    public static void reverse(int[] nums, int start, int end) {
        while (start < end) {
            int temp = nums[start];
            nums[start] = nums[end];
            nums[end] = temp;

            start++;
            end--;
        }
    }…