Generate all unique permutations?

gistfile1.cpp

#include <vector>
#include <algorithm>
#include <iostream>
#include <ostream>
#include <iterator>

template<typename T>
void print(const std::vector<T>& v)
{
    std::copy(v.begin(), v.end(), std::ostream_iterator<T>(std::cout));
    std::cout << std::endl;
}

template<typename T>
void permute(std::vector<T>& v, int i = 0)
{
    if (i == (int)v.size())
        print(v);
    else
    {
        T last = T();
        for(int j = i, e = v.size(); j< e; ++j)
        {
            if ( j!= i && last == v[j])
                continue;
            last = v[j];
            std::swap(v[i], v[j]);
            permute(v, i+1);
            std::swap(v[i], v[j]);
        }
    }
}

int main()
{
    //int arr[] = {1,2,2,3};
    //std::vector<int> v(arr, arr+sizeof(arr)/sizeof(arr[0]));
    char arr[] = "Hello";
    std::vector<char> v(arr, arr+sizeof(arr)/sizeof(arr[0])-1);
    std::sort(v.begin(), v.end());
    permute(v);
}