I've wrote combination program in c++ but there is no output ,can any one tell why? : this combination program without result, can anyone help me ?
     `#include <iostream>
      #include<cstring>
      using namespace std;
      void comb(char *inp)
      {
      int i, j, k;
       int len = strlen(inp);

      for (i = 0; i < len - 2; i++)
    {
        for (j = i + 1; j < len - 1; j++)
        {
            for (k = j + 1; k < len; k++)
                printf("%c%c%c\n", inp[i], inp[j], inp[k]);
        }
        }
      }
    int main ()
     {
	   string str,z;
	   std::cout<<"enter your string";
	   cin>>str;
	   z=comb(str);
	   return 0;
     }`

    