01-01-2.cpp

more efftive 代码

// VC6[x] BCB4[x] GCC295[o]

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;

class line_iterator
{
  istream* in;
  string line;
  bool is_valid;
  void read() {
    if (*in)
      getline(*in, line);
    is_valid = (*in) ? true : false;
  }

public:
  typedef input_iterator_tag iterator_category;
  typedef string value_type;
  typedef ptrdiff_t difference_type;
  typedef const string* pointer;
  typedef const string& reference;
  
  line_iterator() : in(&cin), is_valid(false) {}
  line_iterator(istream& s) : in(&s) { read(); }
  reference operator*() const { return line; }
  pointer operator->() const { return &line; }
  line_iterator operator++() {
    read();
    return *this;
  }
  line_iterator operator++(int) {
    line_iterator tmp = *this;
    read();
    return tmp;
  }
  bool operator==(const line_iterator& i) const {
    return (in == i.in && is_valid == i.is_valid) ||
           (is_valid == false && i.is_valid == false);
  }
  
  bool operator!=(const line_iterator& i) const {
    return !(*this == i);
  }
};


int main() {
  line_iterator iter(cin);
  line_iterator end_of_file;
  vector<string> V(iter, end_of_file);
  sort(V.begin(), V.end());
  copy(V.begin(), V.end(), ostream_iterator<string>(cout, "\n"));
}