Interview Coding Java Sorting

java

Solution

Use `indexOf()` to extract words from your string instead of `split(" ")`. It improves performance.

See this thread: Performance of StringTokenizer class vs. split method in Java

Also, try to increase the size of the output, copy-paste the line Sachin Tendulkar scored 18111 ODI runs and 14692 Test runs. 50,000 times in the text file and measure the performance. That way, you will be able to see considerable time difference when you try different optimizations.

EDIT

Tested this code (used `.indexOf()`)

        long st = System.currentTimeMillis();
        int v = 0;
        List ls = new ArrayList();
        // To read data from file
        BufferedReader in = new BufferedReader(new FileReader("D:\\File.txt"));
        String read = in.readLine().toLowerCase();
        read.replaceAll("\\.", "");
        int pos = 0, end;
        while ((end = read.indexOf(' ', pos)) >= 0) {
            String curString = read.substring(pos,end);
            pos = end + 1;
        // Check for the array if it matches number
            try {
                // Adding the numbers
                v += Integer.parseInt(curString);
            }
            catch (NumberFormatException e) {
                // sorting the characters
                char[] c = curString.toCharArray();
                Arrays.sort(c);
                String r = new String(c);
                // Adding the resulting word into TreeSet
                ls.add(r);
            }
        }
        //sorting the list
        Collections.sort(ls);
        //adding the number
        list.add(v);
        // Displaying the string using Iteartor 
        Iterator<String> it = ls.iterator();
        while (it.hasNext()) {
            System.out.print(it.next() + " ");
        }
        long time = System.currentTimeMillis() - st;
        System.out.println("\n Time Taken: " + time + " ms");

Performance using 1 line in file Your code: 3 ms My code: 2 ms

Performance using 50K lines in file Your code: 45 ms My code: 32 ms

As you see, the difference is significant when the input size increases. Please test it on your machine and share results.

Problem

Original source

Related problems

• Performance of StringTokenizer class vs. String.split method in Java