Is Sort Array By Parity easy or hard?

Sort Array By Parity is classified as an Easy problem. The main concept is recognizing that full sorting is unnecessary and that a simple partition using two pointers can solve it in linear time.

Sort Array By Parity Python/Java solution

In Python or Java, iterate using two indices and swap elements when an odd number appears on the left and an even number appears on the right. The same logic works in C++, C#, and JavaScript with identical O(n) time and O(1) space complexity.

How to solve Sort Array By Parity in O(n)?

Traverse the array with two pointers. Move the left pointer until it finds an odd number and move the right pointer until it finds an even number. Swap them and continue until the pointers cross. This partitions the array in a single linear pass.

What is the best approach for Sort Array By Parity?

The two-pointer technique is the most efficient approach. Use one pointer from the start and another from the end, swapping misplaced odd and even numbers. This partitions the array in O(n) time while using O(1) extra space.

Is Sort Array By Parity asked at Google/Amazon/Meta?

Parity and partition-style array problems frequently appear in interviews at large tech companies such as Amazon, Google, and Meta. While this exact question may vary, the underlying two-pointer partition pattern is commonly tested.

What data structure is used in Sort Array By Parity?

The problem primarily uses arrays and pointer manipulation. The optimal solution relies on the two-pointer technique to partition elements in place without additional data structures.

What is the time complexity of Sort Array By Parity?

The optimal solution runs in O(n) time because each element is examined at most once during the partition process. The in-place two-pointer approach also keeps the space complexity at O(1).

905. Sort Array By Parity - Practice Online

Given an integer array nums, move all the even integers at the beginning of the array followed by all the odd integers.

Return any array that satisfies this condition.

Example 1:

Input: nums = [3,1,2,4]
Output: [2,4,3,1]
Explanation: The outputs [4,2,3,1], [2,4,1,3], and [4,2,1,3] would also be accepted.

Example 2:

Input: nums = [0]
Output: [0]

Constraints:

1 <= nums.length <= 5000
0 <= nums[i] <= 5000