Solution2.js

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var sortArray = function (nums) {
    function mergetSort(l, r) {
        if (l >= r) {
            return;
        }
        const mid = (l + r) >> 1;
        mergetSort(l, mid);
        mergetSort(mid + 1, r);
        let [i, j, k] = [l, mid + 1, 0];
        while (i <= mid && j <= r) {
            if (nums[i] <= nums[j]) {
                tmp[k++] = nums[i++];
            } else {
                tmp[k++] = nums[j++];
            }
        }
        while (i <= mid) {
            tmp[k++] = nums[i++];
        }
        while (j <= r) {
            tmp[k++] = nums[j++];
        }
        for (i = l, j = 0; i <= r; ++i, ++j) {
            nums[i] = tmp[j];
        }
    }
    const n = nums.length;
    let tmp = new Array(n).fill(0);
    mergetSort(0, n - 1);
    return nums;
};