import java.util.Arrays;
import java.util.Random;

public class EfficiencyTest {
    private static final int NUMBER_OF_TESTS = 10000;
    private static long startTime = -1;

    public static void startTimer() {
        EfficiencyTest.startTime = System.nanoTime();
    }

    /** pre: startTimer has been called and EfficiencyTest.startTime != -1 */
    public static long stopTimer() {
        long start = EfficiencyTest.startTime;

        /* Reset the startTime */
        EfficiencyTest.startTime = -1; 

        return System.nanoTime() - start;
    }

    /* pre: array.length >= 1 */
    public static long average(long[] array) {
        long average = array[0];
        for (int i = 1; i < array.length; i++) {
            average = (average * i + array[i]) / (i+1);
        }
        return average;
    }

    public static void prints1() {
        System.out.println("hello");
    }

    public static void prints2() {
        System.out.print("h");
        System.out.print("e");
        System.out.print("l");
        System.out.print("l");
        System.out.println("o");
    }
 
    public static void main(String[] args) {
        long[] times1 = new long[EfficiencyTest.NUMBER_OF_TESTS];
        long[] times2 = new long[EfficiencyTest.NUMBER_OF_TESTS];

        for (int i = 0; i < EfficiencyTest.NUMBER_OF_TESTS; i++) {
            
            /* Test prints1 */
            EfficiencyTest.startTimer();
            prints1();
            times1[i] = EfficiencyTest.stopTimer();

            /* Test prints2 */
            EfficiencyTest.startTimer();
            prints2();
            times2[i] = EfficiencyTest.stopTimer();
        }

        System.out.println("prints1 average run time is " + average(times1) + " ns.");
        System.out.println("prints2 average run time is " + average(times2) + " ns.");

    }
}