11. Sort Array By Parity

Title：

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:

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

Note:

1. 1 <= A.length <= 5000
2. 0 <= A[i] <= 5000

Analysis of Title：

Nothing need to analyse.

Test case：

[3,1,2,4]

Python：

class Solution(object):
　　def sortArrayByParity(self, A):
　　"""
　　:type A: List[int]
　　:rtype: List[int]
　　"""
　　i=0
　　for j in range(len(A)):
　　　　if A[j] % 2 == 0:
　　　　　　A[i], A[j] = A[j], A[i]
　　　　　　i += 1
　　return A

Analysis of Code：

Noticing the outside 'i=0', recall the Bubble Sorting。

Bubble Sorting uses two iterations to get a former and a later.