int binarySearch(const int myArray[], int end, int target, int* locn){
    // Binary Search Function
    //
    // Inputs: Array to sort, index of last element,
    //          value to search for, pointer to location
    //          to store the index of the value if found
    // Outputs: Returns 1 if value found, 0 if not
    //          Modifies the value corresponding to the pointer
    //
    // local variables
    int first;
    int mid;
    int last;

    // algorithm
    first = 0;
    last = end;

    while(first <= last){
		// calculate mid
		mid = (first + last)/2;
	
		// check value
		if(target > myArray[mid])
			// upper half
			first = mid + 1;
		else if(target < myArray[mid])
			// lower half
			last = mid - 1;
		else
			// found
			first = last + 1;
	} // end while

	// set value of index
	// using a pointer to allow multiple returns
	*locn = mid;

	// set return to 1 if found, 0 if not found
	return (target == myArray[mid]);
} // end binarySearch