<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 necessairly 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>

class Solution {
public:


    vector<int> nums;

    void solve(int l, int m,int r) {
        int left = l;
        int right = m+1;

        vector<int> newarr(r-l+1,0);
        int k = 0;
        while(left <=m && right <= r) {
            if (nums[left] < nums[right]) {
                newarr[k++] = nums[left++];
            } else if (nums[left] > nums[right]) {
                newarr[k++] = nums[right++];
            } else {
                newarr[k++] = nums[left++];
                newarr[k++] = nums[right++];
            }
        }

        while(left<=m) {
            newarr[k++] = nums[left++];
        }

        while(right<= r) {
            newarr[k++] = nums[right++];
        }

        k = 0;
        for (int i = l;i<=r;i++) {
            nums[i] =  newarr[k++];
        }
    }

    void mergesort(int l,int r) {
        if (l >= r) return;


        int mid = (l+r)/2;

        mergesort(l,mid);
        mergesort(mid+1,r); 
        solve(l,mid,r);
    }
    vector<int> sortArray(vector<int>& nums) {
        this->nums = nums;

        mergesort(0, (int) nums.size()-1);
        return this->nums;
    }
};
146963