Anagrams in C++

anagrammer.cpp

//
//  main.cpp
//  anagrammer
//
//  Created by Dave Kennedy on 29/11/2016.
//  Copyright © 2016 Dave Kennedy. All rights reserved.
//

#include <string>
#include <vector>
#include <stack>
#include <iostream>

using namespace std;

vector <string> vary (char c, const string& word) {
    vector<string> variations;
    string to_insert (&c, 1);
    for (size_t pos = 0; pos <= word.length(); pos++) {
        string temp_word = word;
        temp_word.insert(pos, to_insert);
        variations.push_back(temp_word);
    }
    return variations;
}

vector <string> anagram (const string& word) {
    vector <string> anagrams;
    vector <string> intermediates;
    stack <char> chars;
    
    for_each(word.begin(), word.end(), [&](char c){chars.push(c);});
    intermediates.push_back ("");
    while (chars.size() > 0) {
        anagrams.clear();
        char c = chars.top();
        chars.pop();
        for (auto word : intermediates) {
            vector<string> variations = vary (c, word);
            anagrams.insert(anagrams.end(), variations.begin(), variations.end());
        }
        intermediates = anagrams;
    }
    return anagrams;
}

int main(int argc, const char * argv[]) {
    // insert code here...
    for (auto word : anagram("abc")) {
        cout << word << endl;
    }
    return 0;
}