int rangeLower = 0;
int rangeUpper = dictionary.size() - 1;
int rangeMiddle;
searches = 0;
while(rangeLower <= rangeUpper)
{
    searches++;
    rangeMiddle = (rangeUpper - rangeLower) / 2 + rangeLower;
    if (str.compareTo(dictionary.get(rangeMiddle)) < 0)
        rangeUpper = rangeMiddle - 1;
    else if (str.compareTo(dictionary.get(rangeMiddle)) > 0)
        rangeLower = rangeMiddle + 1;
    else
        return rangeMiddle;
}
return -1;