#include <iostream>
#include <fstream>
#include <string>
#include <vector>

vector<string> read_dictionary(string filename)
{ vector<string> d;
  ifstream fin(filename.c_str());
  while (true)
  { string s;
    fin >> s;
    if (fin.fail()) break;
    d.push_back(s); }
  fin.close();
  cout << d.size() << " words read\n";
  return d; }

void search(vector<string> v)
{ int min = 0, max = v.size()-1, steps = 0;
  while (true)
  { int middle = (min+max)/2;
    steps += 1;
    string whichway;
    cout << steps << ": " << min << " " << middle << " "
         << max << " " << v[middle] << "\n? ";
    cin >> whichway;
    if (whichway == "before")
      max = middle - 1;
    else if (whichway == "after")
      min = middle + 1;
    else
      cout << "idiot!\n"; } }

void main()
{ vector <string> words = read_dictionary("/home/www/dics/pocket.txt");
  cout << words[0] << "\n";
  cout << words[words.size()/2] << "\n";
  cout << words[words.size()-1] << "\n";
  cout << "\nThink of a word, tell me 'before' or 'after' relative to the one I say.\n";
  search(words); }