## 题目

Given an array `A`

of non-negative integers, return an array consisting of all the even elements of `A`

, followed by all the odd elements of `A`

.

You may return any answer array that satisfies this condition.

Example 1:

1 | Input: [3,1,2,4] |

**Note:**

`1 <= A.length <= 5000`

`0 <= A[i] <= 5000`

## 思路

- Approach 1: Sort

Use a custom comparator when sorting, to sort by parity.

Time Complexity: O(NlogN), Space Complexity: O(N) - Approach 2: Two Pass

Write all the even elements first, then write all the odd elements.

Time Complexity: O(N), Space Complexity: O(N) - Approach 3: In-Place

Like quicksort.

Time Complexity: O(N), Space Complexity: O(1)

## 代码

1 | class Solution(object): |