#include <stdio.h>
#define EOA -1 /*end of array, hacky way to signal the last array element*/

int binSearch(int ar[], int x);

int main (){
    int array[50] = {2,5,7,10,14,17,20,23,25,31,33,36,37,EOA};

    printf("%i",binSearch(array, 23));

    return 0;

}

int binSearch(int ar[], int x){
    int i, midPoint;
    for (i = 0; ar[i] != EOA; ++i);
    if (i % 2 == 0)
        midPoint = i/2;
    else
        midPoint = (i/2)+1;
    while (1){
        if (x < ar[midPoint])
            midPoint = midPoint*1/2;
        if (x > ar[midPoint])
            midPoint = midPoint*3/2;
        else
            return midPoint;
        }
}