<p>Given an integer array <code>nums</code> and an integer <code>k</code>, return <em>the</em> <code>k<sup>th</sup></code> <em>largest element in the array</em>.</p>

<p>Note that it is the <code>k<sup>th</sup></code> largest element in the sorted order, not the <code>k<sup>th</sup></code> distinct element.</p>

<p>Can you solve it without sorting?</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> nums = [3,2,1,5,6,4], k = 2
<strong>Output:</strong> 5
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> nums = [3,2,3,1,2,4,5,5,6], k = 4
<strong>Output:</strong> 4
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= k &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>-10<sup>4</sup> &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
</ul>

class Solution {
public:
    int findKthLargest(std::vector<int>& nums, int k) {
        int left = 0, right = nums.size() - 1;
        while (true) {
            int pivot_index = rand() % (right - left + 1) + left;
            int new_pivot_index = partition(nums, left, right, pivot_index);
            if (new_pivot_index == nums.size() - k) {
                return nums[new_pivot_index];
            } else if (new_pivot_index > nums.size() - k) {
                right = new_pivot_index - 1;
            } else {
                left = new_pivot_index + 1;
            }
        }
    }

private:
    int partition(std::vector<int>& nums, int left, int right, int pivot_index) {
        int pivot = nums[pivot_index];
        std::swap(nums[pivot_index], nums[right]);
        int stored_index = left;
        for (int i = left; i < right; i++) {
            if (nums[i] < pivot) {
                std::swap(nums[i], nums[stored_index]);
                stored_index++;
            }
        }
        std::swap(nums[right], nums[stored_index]);
        return stored_index;
    }
};
58000