string permutation

/* 8_4 Write a method to compute all permutations of a string. */

void permutations(string s, bool * b, string word, set<string> & ss) {

    if (s.size() == word.size()) {

        ss.insert(word);

        return;

    }

    for (int i = 0; i < s.size(); ++i) {

        if (!b[i]) {

            b[i] = true;

            word.append(s.substr(i, 1));

            permutations(s, b, word, ss);

            word.erase(word.size()-1);

            b[i] = false;

        }

    }

}

void allPermutation(string s) {

    set<string> ss;

    set<string>::iterator it;

    bool * b = new bool[s.size()-1];

    permutations(s, b, "", ss);

    for (it = ss.begin(); it != ss.end(); it++) {

        cout << *it << endl;

    }

    delete [] b;

   

}