922.sort-array-by-parity-ii.js

/*
 * @lc app=leetcode id=922 lang=javascript
 *
 * [922] Sort Array By Parity II
 *
 * https://leetcode.com/problems/sort-array-by-parity-ii/description/
 *
 * algorithms
 * Easy (67.16%)
 * Likes:    356
 * Dislikes: 36
 * Total Accepted:    59.3K
 * Total Submissions: 88.3K
 * Testcase Example:  '[4,2,5,7]'
 *
 * 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
 * 
 * 
 * 
 * 
 * 
 */

// @lc code=start
/**
 * @param {number[]} A
 * @return {number[]}
 */
var sortArrayByParityII = function (A) {
    let odd = [];
    let even = [];
    A.forEach(item => {
        if (item % 2 === 0) {
            even.push(item);
        } else {
            odd.push(item);
        }
    });
    return Array(A.length).fill(null).map((item, i) => {
        if (i % 2 === 0) {
            return even.pop();
        } else {
            return odd.pop();
        }
    })
};
// @lc code=end