922. Sort Array By Parity II

Given an array A of non-negative integers, half of the integers in A are odd, and half of the integers are even.

Sort the array so that whenever A[i] is odd, i is odd; and whenever A[i] is even, i is even.

You may return any answer array that satisfies this condition.

两个指针，一个是奇一个是偶，for一遍数组，是奇数就放到奇数指针的位置，偶数就放到偶数指针位置。

class Solution(object):
    def sortArrayByParityII(self, A):
        """
        :type A: List[int]
        :rtype: List[int]
        """
        ans = [0] * len(A)
        even_index = 0
        odd_index = 1
        for value in A:
            if value % 2 == 0:
                ans[even_index] = value
                even_index += 2
            else:
                ans[odd_index] = value
                odd_index += 2
        return ans