IP

ip.c

void dfs(int start, int count, string &s, 
         vector<string> &tmp, vector<vector<string> > &result)
{
         if (start == s.size() && count == 0) {
                   result.push_back(tmp);
                  return ;
         }

         for (int i = start; i < s.size(); i++) {
                  tmp.push_back(s.substr(start, i-start+1));
                  dfs(i+1, count-1, s, tmp, result);
                  tmp.pop_back();
         }
}