922. Sort Array By Parity II #

题目 #

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.

Example 1:

Input: [4,2,5,7]
Output: [4,5,2,7]
Explanation: [4,7,2,5], [2,5,4,7], [2,7,4,5] would also have been accepted.

Note:

• 2 <= A.length <= 20000
• A.length % 2 == 0
• 0 <= A[i] <= 1000

题目大意 #

要求数组中奇数下标位置上放奇数，偶数下标位置上放偶数。

解题思路 #

这题比较简单，用两个下标控制奇数，偶数放置在哪个下标即可。奇数奇数之间，偶数偶数之间的顺序可以是无序的。

代码 #

package leetcode

func sortArrayByParityII(A []int) []int {
	if len(A) == 0 || len(A)%2 != 0 {
		return []int{}
	}
	res := make([]int, len(A))
	oddIndex := 1
	evenIndex := 0
	for i := 0; i < len(A); i++ {
		if A[i]%2 == 0 {
			res[evenIndex] = A[i]
			evenIndex += 2
		} else {
			res[oddIndex] = A[i]
			oddIndex += 2
		}
	}
	return res
}