#include <iostream>
#include <string>

using namespace std;

int BinarySearch(string s, int start, int stop, char key) ;

int main () {
    string array = "bcfghmqtvy";
    char c;
    int pos;

    for(c = 'a'; c<= 'z';c++) {
       pos = BinarySearch(array, 0, array.size()-1, c);
       if (-1 == pos) {
          cout << c << " is not in " << array << endl;
       } else {
          cout << c << " is at position " << pos << " of " << array << endl;
       }
    }
    
    return 0;
}


int BinarySearch(string s, int start, int stop, char key) {
    int mid;
    if (start > stop) {
        // we need some indication of not found
        return -1;
    } else {
        mid = (start + stop) /2;
        if (s[mid] == key) {
           return mid;
        } else if (key < s[mid]){
           return BinarySearch(s,start, mid-1, key);
        } else {
           return BinarySearch(s,mid+1,stop, key);
        }
    }
}