#922. Sort Array By Parity II

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.

这道题的意思是，把A中的奇数放在奇数位，偶数放在偶数位。首先把奇数和偶数用两个数组保存，然后再按照这个要求拼接成一个数组。

/**
 * @param {number[]} A
 * @return {number[]}
 */
var sortArrayByParityII = function(A) {
    var evenArr = [];
    var oddArr = [];
    for(var i=0;i<A.length;i++) {
        if(A[i]%2===0) {
            evenArr.push(A[i]);
        }
        else {
            oddArr.push(A[i]);
        }
    }
    var resArr = [];
    for(var j=0;j<A.length;j++) {
        if(j%2===0) {
            resArr.push(evenArr[0]);
            evenArr.splice(0,1);
        }
        else {
            resArr.push(oddArr[0]);
            oddArr.splice(0,1);
        }
    }
    return resArr;
};