#include <stdio.h>
#include <limits.h>

/*
Napisz funkcje, ktora dla tablicy n liczb calkowitych A, w ktorej nie wszystkie
wyrazy sa rowne, zwroci drugi co do wielkosci element w tablicy.

Przyklad: Dla tablicy A = [2, 3, 5, 11, -1, 11, 8, 4], funkcja powinna zwrocic
wartosc 8
*/

int secondLargest(int arr[], int size) {
    int largest = arr[0];        //first element is set as the largest at the beginning
    int secondLargest = INT_MIN; //here we need to set this variable to the smallest possible (TODO: study limits.h)

    //iterate over array only once
    for (int i = 1; i < size; i++) {
        if (arr[i] > largest) {  //shifting largest as secondLargest if needed
            secondLargest = largest;
            largest = arr[i];
        }
        //heavy duty part
        else if (arr[i] < largest && (secondLargest == INT_MIN || arr[i] > secondLargest)) {
            secondLargest = arr[i];
        }
    }

    return secondLargest;
}

int secondLargestNaive(int arr[], int size) {
    //naive algorithm (iterate over array twice)
    int largest = INT_MIN;

    for (int i = 0; i < size; i++)
        if (arr[i]>largest) largest=arr[i];

    int secondLargest = INT_MIN;
    for (int i = 0; i < size; i++)
        if (arr[i]>secondLargest && arr[i]!=largest) secondLargest=arr[i];

     return secondLargest;
}

int main() {

    int A[] = {2, 3, 5, 11, -1, 11, 8, 4};
    int size = sizeof(A) / sizeof(A[0]);

    int result = secondLargest(A, size);
    printf("Drugi co do wielkosci element w tablicy to: %d\n", result);

    result = secondLargestNaive(A, size);
    printf("Drugi co do wielkosci element w tablicy to: %d\n", result);
    return 0;
}