703298. Rotate Array by One
Rotate Array by One
Slug: cyclically-rotate-an-array-by-one2614 Difficulty: Basic Id: 703298 Topic Tags: Arrays, implementation Company Tags: None
Summary
Rotate Array by One is a basic problem that involves rotating an array by one position. This means the last element of the array becomes the first, and all other elements are shifted accordingly. The key concept involved in this problem is array manipulation.
Detailed Explanation
The approach to solve this problem is straightforward. We can achieve this by using two pointer variables, one at the beginning and another at the end of the array. We then swap the values of these pointers until they meet in the middle. This effectively rotates the array by one position.
Here's a step-by-step breakdown of the solution:
- Initialize two pointers,
startandend, to the first and last elements of the array respectively. - While
startis not equal toend, swap the values at these positions and move the pointers towards each other. - Once
startmeetsend, the rotation is complete.
Time Complexity: O(n), where n is the size of the array, as we are traversing the entire array once. Space Complexity: O(1), as we are not using any extra space that scales with the input size.
Optimized Solutions
Java
public static void rotateArray(int[] arr) {
int start = 0;
int end = arr.length - 1;
while (start != end) {
int temp = arr[start];
arr[start] = arr[end];
arr[end] = temp;
start++;
end--;
}
}