Algorithm to print all combination of letters of the given string in lexicographical order

Question

I tried to create the code to generate all possible combination of the given string in the lexicographical order:

The code that I wrote is:

void get(         


        

Answer 1

This is a simple recursive approach:

#include 
#include 
using namespace std;

void get( string str, string res ) {

   cout << res << endl;

   for( int i = 0; i < str.length(); i++ )
      get( string(str).erase(i,1), res + str[i] );
}

int main( int argc, char **argv) {

   string str = "abcde";
   get( str, "" );  
   return 0;
}

Maybe not the most efficient way of doing it, but a short and simple one. Keep in mind, that enumerating all combinations has a complexity of O(2ⁿ) anyway. So there exists no efficient algorithm at all.