Count number of different letters in word in array.

DifferentElements.c++

inline unsigned calcStates () {
    unsigned numStates = (unsigned) substrings[0].size() + 1;
    Word str1, str2;
    for ( vector<Word>::iterator str = substrings.begin(); (str+1) != substrings.end(); ) {
        str1 = *str;
        str2 = *(++str);
        
        unsigned i = 0;
        while (str1[i] == str2[i] && i < str1.size()) i++;
        
        numStates += (unsigned) str2.size() - i;
    }
    
    return numStates;
}