leetcode-按奇偶排序数组II

Python解决方法：

class Solution(object):
    def sortArrayByParityII(self, A):
        j = 1
        for i in xrange(0, len(A), 2):
            if A[i] % 2:
                while A[j] % 2:
                    j += 2
                A[i], A[j] = A[j], A[i]
        return A

class Solution(object):
    def sortArrayByParityII(self, A):
        N = len(A)
        ans = [None] * N

        t = 0
        for i, x in enumerate(A):
            if x % 2 == 0:
                ans[t] = x
                t += 2

        t = 1
        for i, x in enumerate(A):
            if x % 2 == 1:
                ans[t] = x
                t += 2

        # We could have also used slice assignment:
        # ans[::2] = (x for x in A if x % 2 == 0)
        # ans[1::2] = (x for x in A if x % 2 == 1)

        return ans