SystemSort.java

Below is the syntax highlighted version of SystemSort.java from §4.2 Sorting and Searching.

/*************************************************************************
 *  Compilation:  javac SystemSort.java
 *  Execution:    java SystemSort N < mobydick.txt
 *  
 *
 *************************************************************************/

import java.util.Arrays;

public class SystemSort {

    public static double timeit(int N) {
        double[] a = new double[N];
        for (int i = 0; i < N; i++) a[i] = Math.random();
        long start = System.currentTimeMillis(); 
        Arrays.sort(a);
        long stop = System.currentTimeMillis();
        return (stop - start) / 1000.0;
    }

    public static void main(String[] args) {
        int N = Integer.parseInt(args[0]);
        for (int i = 0; i < 100; i++)
            System.out.println(timeit(N));
    }
}