Kth Largest Element in an Array
Problem Statement - link #
Given an integer array nums and an integer k, return the kth largest element in the array.
Note that it is the kth largest element in the sorted order, not the kth distinct element.
Examples #
Example 1:
Input: nums = [3,2,1,5,6,4], k = 2
Output: 5
Example 2:
Input: nums = [3,2,3,1,2,4,5,5,6], k = 4
Output: 4
Constraints #
1 <= k <= nums.length <= 10^4-10^4 <= nums[i] <= 10^4
Solutions #
class Solution{
public:
int lomutoPartition(vector<int> &nums, int l, int r){
int pivot = nums[r];
int start = l;
for(int i=l; i<r; i++)
if(nums[i]<pivot) swap(nums[start++], nums[i]);
swap(nums[r], nums[start]);
return start;
}
int findKthLargest(vector<int>& nums, int k) {
int l = 0, r = nums.size()-1, n=nums.size();
k = n - k + 1;
while(l<=r){
int p = lomutoPartition(nums, l, r);
if(p==k-1) return nums[p];
else if(p > k-1) r = p - 1;
else l = p + 1;
}
return -1;
}
};