# 922. Sort Array By Parity II

## Description

Given an array of integers nums, half of the integers in nums are odd, and the other half are even.

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

Return any answer array that satisfies this condition.

Example 1:

Input: nums = [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.


Example 2:

Input: nums = [2,3]
Output: [2,3]


Constraints:

• 2 <= nums.length <= 2 * 104
• nums.length is even.
• Half of the integers in nums are even.
• 0 <= nums[i] <= 1000

Follow Up: Could you solve it in-place?

## Solutions

• class Solution {
public int[] sortArrayByParityII(int[] nums) {
for (int i = 0, j = 1; i < nums.length; i += 2) {
if ((nums[i] & 1) == 1) {
while ((nums[j] & 1) == 1) {
j += 2;
}
int t = nums[i];
nums[i] = nums[j];
nums[j] = t;
}
}
return nums;
}
}

• class Solution {
public:
vector<int> sortArrayByParityII(vector<int>& nums) {
for (int i = 0, j = 1; i < nums.size(); i += 2) {
if ((nums[i] & 1) == 1) {
while ((nums[j] & 1) == 1) {
j += 2;
}
swap(nums[i], nums[j]);
}
}
return nums;
}
};

• class Solution:
def sortArrayByParityII(self, nums: List[int]) -> List[int]:
n, j = len(nums), 1
for i in range(0, n, 2):
if (nums[i] & 1) == 1:
while (nums[j] & 1) == 1:
j += 2
nums[i], nums[j] = nums[j], nums[i]
return nums


• func sortArrayByParityII(nums []int) []int {
for i, j := 0, 1; i < len(nums); i += 2 {
if (nums[i] & 1) == 1 {
for (nums[j] & 1) == 1 {
j += 2
}
nums[i], nums[j] = nums[j], nums[i]
}
}
return nums
}

• /**
* @param {number[]} nums
* @return {number[]}
*/
var sortArrayByParityII = function (nums) {
for (let i = 0, j = 1; i < nums.length; i += 2) {
if ((nums[i] & 1) == 1) {
while ((nums[j] & 1) == 1) {
j += 2;
}
[nums[i], nums[j]] = [nums[j], nums[i]];
}
}
return nums;
};


• function sortArrayByParityII(nums: number[]): number[] {
for (let i = 0, j = 1; i < nums.length; i += 2) {
if (nums[i] % 2) {
while (nums[j] % 2) {
j += 2;
}
[nums[i], nums[j]] = [nums[j], nums[i]];
}
}
return nums;
}