find kth max and min element in an array

To find the kth maximum and minimum element in an array in C++, you can follow these steps:

First, sort the array in ascending order using the std::sort function from the <algorithm> library. This will arrange the elements in the array in increasing order.
To find the kth minimum element, you can simply access the element at index k-1 in the sorted array. Since arrays are zero-indexed, the kth minimum element will be at index k-1.
To find the kth maximum element, you can access the element at index n-k in the sorted array, where n is the size of the array. Since arrays are zero-indexed, the kth maximum element will be at index n-k.

Here's an example implementation that demonstrates these steps:

#include <iostream>
#include <algorithm>

int main() {
    int arr[] = {5, 2, 9, 1, 7, 3};
    int n = sizeof(arr) / sizeof(arr[0]);
    int k = 3;

    std::sort(arr, arr + n);

    int kthMin = arr[k - 1];
    int kthMax = arr[n - k];

    std::cout << "The kth minimum element is: " << kthMin << std::endl;
    std::cout << "The kth maximum element is: " << kthMax << std::endl;

    return 0;
}

In this example, we have an array arr with elements {5, 2, 9, 1, 7, 3}. We want to find the 3rd minimum and maximum elements. After sorting the array in ascending order, we can access the element at index k-1 (2) to get the 3rd minimum element, which is 3. Similarly, we can access the element at index n-k (4) to get the 3rd maximum element, which is 5.

Note: This solution assumes that the value of k is within the range of the array size. If k is greater than the array size or less than 1, the code may produce unpredictable results. It's a good practice to add appropriate validations for the value of k to handle such cases.