2019-03-27-sort array by parity ii

题目，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.

解析

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var sortArrayByParityII = function(A) {
    let result = new Array(A.length);
    for(let i = 0, even = 0, odd = 1; i < A.length; i ++) {
        if(A[i] % 2 === 0) {
            result[even] = A[i];
            even += 2;
        } else {
            result[odd] = A[i];
            odd += 2;
        }
    }
    return result;
};