#include <stdio.h>

#define N 10
#define M 11
#define X 6

void swap(int *max, int *min)
{
    if (*min > *max)
    {
        int temp = *max;
        *max = *min;
        *min = temp;
    }
}

void minmax(int *arr, int n, int *max, int *min)
{
    int Lmax, Rmax, Lmin, Rmin;

    if (n == 0)
    {
        *min = *max = -1;
        return;
    }

    if (n == 1)
    {
        *min = *max = arr[0];
        return;
    }

    if (n == 2)
    {
        *max = arr[0];
        *min = arr[1];
        swap(max,min);
        return;
    }

    minmax(arr,n/2,&Lmax,&Lmin);
    minmax(arr+(n/2),(n/2)+(n%2),&Rmax,&Rmin);

    *max = (Lmax > Rmax)? Lmax : Rmax;
    *min = (Lmin < Rmin)? Lmin : Rmin;
}

int abs(int value)
{
    if (value < 0)
        return value*(-1);
    return value;
}

void findDouble(int *arr, int n)
{
    int i;
    for (i=0;i<n+2;i++)
    {
        if (arr[abs(arr[i]) - 1] < 0)
        {
            printf("Value is: %d\n",arr[i]);
        }
        else
        {
            arr[abs(arr[i]) - 1] = arr[abs(arr[i]) - 1] * (-1);
        }
    }
}

void main()
{
    int max,min;
    int arr1[N] = {3,1,17,9,4,2,27,21,7,10};
    int arr2[M] = {6,5,4,8,1,90,11,21,34,32,33};
    int arr3[X+2] = {1,3,2,2,5,5,6,4};

    findDouble(arr3,X);

    minmax(arr1,N,&max,&min);
    printf("max = %d, min = %d\n",max,min);

    minmax(arr2,M,&max,&min);
    printf("max = %d, min = %d\n",max,min);
}