111. Find Kth Smallest and Kth Largest Element

#include <stdio.h>
#include <stdint.h>

void sort_array(uint8_t *arr, uint8_t n) {
    // Sort in ascending order
    if (!arr || n == 0) return;
    
    for (uint8_t i = 0; i < n; ++i) {
        for (uint8_t j = i + 1; j < n; j++) {
            if (arr[i] > arr[j]) {
                arr[i] = arr[i] - arr[j];
                arr[j] = arr[i] + arr[j];
                arr[i] = arr[j] - arr[i];
            }
        }
    }
}
/*
* 10 3 5 2 7, 
-> sorted: 2 3 5 7 10, k = 2
smallest = arr[2 - 1] 
largest = n - k +  1
*/
void find_kth_elements(uint8_t *arr, uint8_t n, uint8_t k, uint8_t *smallest, uint8_t *largest) {
    // Your logic here
    if (!smallest || !largest) return;
    sort_array(arr, n);

    *smallest = arr[k - 1];
    *largest = arr[n - k];
}

int main() {
    uint8_t n, k;
    scanf("%hhu", &n);
    uint8_t arr[100];
    
    for (uint8_t i = 0; i < n; i++) {
        scanf("%hhu", &arr[i]);
    }

    scanf("%hhu", &k);

    uint8_t smallest, largest;
    find_kth_elements(arr, n, k, &smallest, &largest);

    printf("%hhu %hhu", smallest, largest);
    return 0;
}