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

void max(int *ptr, int lower, int upper, int *maximum)
{
    int mid;
    if(lower == upper){
        if(ptr[lower] > *maximum && ptr[lower]>=100 && ptr[lower]<1000)
            *maximum = ptr[lower];

        return;
    }
    mid = (lower+upper) /2;

    max(ptr, lower, mid, maximum);
    max(ptr, mid+1, upper, maximum);
}

int main()
{
    int n,i,*ptr,maximum=-1000;
    srand(time(NULL));
    n = 100;
    ptr = (int *) malloc(sizeof(int)*n);

    for(i=0 ; i<n; i++)    {
        ptr[i] = rand()%1000;
    }
    max(ptr,0,n-1,&maximum);

    printf("\n Elements count : %d" , n);
    printf("\n Maximum element is : %d", maximum);
    free(ptr);

    return 0;
}