# Solving Leetcode Interviews in Seconds with AI: Sort Array By Parity


	# Introduction
	In this blog post, we will explore how to solve the LeetCode problem "905" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like [Chatmagic](https://www.chatmagic.app), we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

	# Problem Statement
	> 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  

	# Explanation
	Here's the solution to rearrange the array such that even numbers come before odd numbers:

*   **Two-Pointer Approach:** Use two pointers, `left` and `right`, initialized at the beginning and end of the array, respectively.
*   **Move Pointers:** Move the `left` pointer to the right until it points to an odd number and move the `right` pointer to the left until it points to an even number.
*   **Swap:** If `left` is less than `right`, swap the elements at these pointers. Repeat until `left` and `right` cross each other.

*   **Time Complexity:** O(n), **Space Complexity:** O(1)

	
	# Code
	```python
	def sort_array_by_parity(nums: list[int]) -> list[int]:
    """
    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
    """
    left, right = 0, len(nums) - 1

    while left < right:
        if nums[left] % 2 == 0:
            left += 1
        elif nums[right] % 2 != 0:
            right -= 1
        else:
            nums[left], nums[right] = nums[right], nums[left]
            left += 1
            right -= 1

    return nums
	```