uni/inf2440/hw2/Main.java

class Main {
	static int nTests = 1;

	static Timer testFindPrimes(Solver s, int maxNum) {
		Timer[] timers = new Timer[nTests];

		for (int i = 0; i < nTests; ++i) {
			Timer t = timers[i] = new Timer();

			Sieve sieve = new Sieve(maxNum);

			t.start();
			s.solve(sieve);
			t.end();
		}

		return Timer.median(timers);
	}

	static Timer testFactor(Solver s, long maxNum, Sieve sieve) {
		Timer[] timers = new Timer[nTests];

		for (int i = 0; i < nTests; ++i) {
			Timer t = timers[i] = new Timer();
			t.start();
			long n = maxNum * maxNum;
			for (long j = n; j >= n - 100; --j) {

				long[] factors = s.factor(sieve, j);

				if (j > (n - 5) || j < (n - 95)) {
					if (j == n - 96)
						System.out.println(".............");

					System.out.println(
						Util.factors(j, factors));
				}
			}
			t.end();
		}

		return Timer.median(timers);
	}

	public static void main(String[] args) {
		if (args.length == 0) {
			System.out.println("Usage: java Main <biggest prime>");
			System.exit(1);
		}

		Sequential sseq = new Sequential();
		Parallel spar = new Parallel();

		boolean findPrimes = true;
		boolean factor = true;

		int maxNum = Integer.parseInt(args[0]);
		System.out.println("Max prime: "+maxNum);

		if (findPrimes) {
			System.out.println("\nFinding primes sequentially...");
			Timer seq = testFindPrimes(sseq, maxNum);
			System.out.println("Sequential: "+seq.prettyTime());

			System.out.println("\nFinding primes in parallel...");
			Timer par = testFindPrimes(spar, maxNum);
			System.out.println("Parallel: "+par.prettySpeedup(seq));
		}

		if (factor) {
			// We need a solved sieve
			Sieve sieve = new Sieve(maxNum);
			spar.solve(sieve);
			sieve.getPrimes();

			System.out.println("\nFactoring sequentially...");
			Timer seq = testFactor(sseq, maxNum, sieve);
			Timer seqAvg = new Timer(seq.time / 100);
			System.out.println(
				"Sequential: "+seq.prettyTime()+
				" ("+seqAvg.prettyTime()+" per factor)");

			System.out.println("\nFactoring in parallel...");
			Timer par = testFactor(spar, maxNum, sieve);
			Timer parAvg = new Timer(par.time / 100);
			System.out.println(
				"Parallel: "+par.prettySpeedup(seq)+
				" ("+parAvg.prettyTime()+" per factor)");
		}

		spar.stopThreads();
	}
}