UNIQUE PERMUTATIONS

#include<iostream>
#include<string>
#include<map>
#include<algorithm>
void gen_perm(std::map<std::string,int> &m,std::string s,int i,int n)
{
  if(i==n-1)
    m[s]++;
  else
  {
    for(int j=i;j<n;++j)
    {
    std::swap(s[i],s[j]);
    gen_perm(m,s,i+1,n);
    std::swap(s[i],s[j]);
    }
  }
}
void gen_perm_stl(std::string s)
{
  std::sort(s.begin(),s.end());
  do
    std::cout<<s<<"\n";
  while(std::next_permutation(s.begin(),s.end()));
}
int main()
{
  std::string s;
  std::map<std::string,int> m;
  std::cout<<"Enter a string: ";
  std::cin>>s;
  std::cout<<"\nPermutations: \n";
  //gen_perm_stl(s); // call any one function.. stl obviously performs better
  gen_perm(m,s,0,s.length());
  for(auto it=m.begin();it!=m.end();++it)
    std::cout<<it->first<<"\n";
}