#include <stdio.h>
#include <string>
#include <vector>

int factorial(int n)
{
    for(int i = n-1; i > 1; --i)
        n *= i;
    return n;
}

std::vector<std::string> permutar2(const std::string& text)
{
    std::vector<std::string> permut;
    int factorialLength = factorial(text.length());
    int factorialLength1 = factorial(text.length()-1);
    permut.resize(factorialLength);

    if(text.length() == 2) {
        permut.resize(factorialLength);
        for(int i = 0; i < factorialLength; ++i)
            for(int j = 0; j < text.length(); ++j)
                permut[i] += text[(i+j) % text.length()];
    }
    else {
        for(int i = 0; i < factorialLength; i+=factorialLength1) {
            char letter = text[(i/factorialLength1) % text.length()];

            for(int j = 0; j < factorialLength1; ++j)
                permut[i+j] += letter;

            std::string ntext;
            for(int j = 0; j < text.length(); ++j) {
                if(text[j] != letter)
                    ntext += text[j];
            }

            std::vector<std::string> permut2 = permutar2(ntext);
            for(int j = 0; j < permut2.size(); ++j)
                permut[i+j] += permut2[j];
        }
    }
    return permut;
}

int main()
{
    std::string text = "abcd";
    std::vector<std::string> permut = permutar2(text);

    for(int i = 0; i < permut.size(); ++i)
        printf("%s\n", permut[i].c_str());


    return 0;
}