gistfile1.hpp

#include <iostream>
#include <vector>
#include <string>
#include <cstdlib> 

using namespace std;

int main(int argc, char* argv[]) { 
  vector<string> lines;
  string line;
  int keep_lines = 5;
  int lines_in_buffer = 0;
  
  if (argc == 2) { 
    keep_lines = atoi(argv[1]);
  }
  
  while (!getline(cin, line, '\n').eof()) {
    lines_in_buffer++;
    lines.insert(lines.begin(), line);
    if (lines_in_buffer > keep_lines) {
      lines.pop_back();  
    }
  }
  
  vector<string>::reverse_iterator rii;
  for (rii = lines.rbegin(); rii != lines.rend(); ++rii) {
    cout << *rii << endl;
  }
}