Sort an Array
<p>Given an array of integers <code>nums</code>, sort the array in ascending order and return it.</p>

<p>You must solve the problem <strong>without using any built-in</strong> functions in <code>O(nlog(n))</code> time complexity and with the smallest space complexity possible.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [5,2,3,1]
<strong>Output:</strong> [1,2,3,5]
<strong>Explanation:</strong> After sorting the array, the positions of some numbers are not changed (for example, 2 and 3), while the positions of other numbers are changed (for example, 1 and 5).
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [5,1,1,2,0,0]
<strong>Output:</strong> [0,0,1,1,2,5]
<strong>Explanation:</strong> Note that the values of nums are not necessarily unique.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 5 * 10<sup>4</sup></code></li>
	<li><code>-5 * 10<sup>4</sup> &lt;= nums[i] &lt;= 5 * 10<sup>4</sup></code></li>
</ul>
Array; Divide and Conquer; Bucket Sort; Counting Sort; Radix Sort; Sorting; Heap (Priority Queue); Merge Sort
class Solution {
    private int[] nums;

    public int[] sortArray(int[] nums) {
        this.nums = nums;
        quikcSort(0, nums.length - 1);
        return nums;
    }

    private void quikcSort(int l, int r) {
        if (l >= r) {
            return;
        }
        int x = nums[(l + r) >> 1];
        int i = l - 1, j = r + 1;
        while (i < j) {
            while (nums[++i] < x) {
            }
            while (nums[--j] > x) {
            }
            if (i < j) {
                int t = nums[i];
                nums[i] = nums[j];
                nums[j] = t;
            }
        }
        quikcSort(l, j);
        quikcSort(j + 1, r);
    }
}