Problem

Given an integer array nums, move all the even integers at the beginning of the array followed by all the odd integers.

Return any array that satisfies this condition.

Example 1:

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

Example 2:

Input: nums = [0] Output: [0]

Constraints:

1 <= nums.length <= 5000 0 <= nums[i] <= 5000

Pre analysis

will just follow the instruction and insert at the beginning of the array and odd at the end of the array

Post analysis

Simple solution, can be done in O(n) time complexity

var sortArrayByParity = function (nums) {
  let i = 0;
  let j = nums.length - 1;
  while (i < j) {
    if (nums[i] % 2 > nums[j] % 2) {
      let temp = nums[i];
      nums[i] = nums[j];
      nums[j] = temp;
    }
    if (nums[i] % 2 === 0) i++;
    if (nums[j] % 2 === 1) j--;
  }
  return nums;
};