Re: Java vs C++ speed (IO & Sorting)

This topic was on these newsgroups 7 years ago :)

http://groups.google.com/group/comp.lang.c++/msg/695ebf877e25b287

I said then: "How about reading the whole Bible, sorting by lines, and
writing the sorted book to a file?"

Who remember that from 7 years ago, one of the longest thread on this
newsgroup :)

The text file used for the bible is here
ftp://ftp.cs.princeton.edu/pub/cs126/markov/textfiles/bible.txt

Back to see if anything has changed

(downloaded whatever is latest version from sun.java.com)

Time for reading, sorting, writing: 359 ms (Java)
Time for reading, sorting, writing: 375 ms (Java)
Time for reading, sorting, writing: 375 ms (Java)

Visual C++ express and command I used was cl IOSort.cpp /O2

Time for reading, sorting, writing: 375 ms (c++)
Time for reading, sorting, writing: 390 ms (c++)
Time for reading, sorting, writing: 359 ms (c++)

The question still is (7 years later), where is great speed advantage
you guys were claiming for c++?

------------------- Java Code -------------- (same as 7 years ago :)

import java.io.*;
import java.util.*;
public class IOSort
{
   public static void main(String[] arg) throws Exception
  {
           ArrayList ar = new ArrayList(5000);

           String line = "";

           BufferedReader in = new BufferedReader(
               new FileReader("bible.txt"));
           PrintWriter out = new PrintWriter(new BufferedWriter(
               new FileWriter("output.txt")));

           long start = System.currentTimeMillis();
           while (true)
           {
               line = in.readLine();
               if (line == null)
                 break;
               if (line.length() == 0)
                continue;
               ar.add(line);
           }

           Collections.sort(ar);
           int size = ar.size();
           for (int i = 0; i < size; i++)
           {
               out.println(ar.get(i));
           }
           out.close();
           long end = System.currentTimeMillis();
          System.out.println("Time for reading, sorting, writing: "+
(end - start) + " ms");
  }
}

--------- C++ Code ---------------

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

int main()
{
  vector<string> buf;
  string linBuf;
  ifstream inFile("bible.txt");
  clock_t start=clock();
  buf.reserve(50000);

  while(getline(inFile,linBuf)) buf.insert(buf.end(), linBuf);
  sort(buf.begin(), buf.end());
  ofstream outFile("output.txt");
  copy(buf.begin(),buf.end(),ostream_iterator<string>(outFile,"\n"));
clock_t endt=clock();
  cout <<"Time for reading, sorting, writing: " << endt-start << "
ms\n";
  return 0;

}