/**
 * File:    Prime.java
 * Project: CMSC 202 Project #0, Fall 2010
 * Author:  John Doe
 * Date:    Sep 8, 2010
 * Section: 14
 * E-mail:  jdoe@umbc.edu 
 * Class Invariants:
 *   None.
 */

/**
 * @author park
 *
 */
public class Prime {

    /**
     * Compute all the prime numbers within the specified range,
     * using the Sieve of Eratosthenes algorithm
     * (@link http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)
     * PreCondition:
     * PostCondition:
     * @param startNum the first number to scan for prime numbers
     * @param endNum the last number to scan
     * @return an exactly-sized array filled with all found primes
     */
    public static int[] findPrimes(int startNum, int endNum) {
	// Make sure you follow all of the requirements outlined in
	// the project description for your implementation.
	// It is guaranteed that startNum >= 2, and startNum <= endNum.
	// You must create a local array of booleans to hold your
	// "sieve" tracking what numbers have been crossed off.
	// You must use a "meaningful" for-loop
	// You must return a fully-filled array of the correct size;
	// in other words, if you found 7 prime numbers in the requested
	// range, your array must be 7 elements long.
	// You must call a helper method (template given below) to
	// process your working array to cancel out all multiples of
	// the next prime found.
    }

    /**
     * Helper method for the Sieve of Eratosthenes algorithm.
     * Given a prime number and an array of booleans, compute all
     * multiples of the prime up to the highest index of the array,
     * and cancel those entries out by setting those array elements
     * to boolean "false".
     * @param prime  the next prime number, to cancel all multiples of
     * @param sieveArray  the array to cancel multiples from
     */
    public static void cancelMultiples(int prime, boolean[] sieveArray) {
	
    }

    /**
     * Test harness for Project 0
     * PreCondition:
     * PostCondition:
     * @param args startNum endNum
     */
    public static void main(String[] args) {
	if (args.length != 2) {
	    System.err.println("args: startNum endNum");
	}
	else {
	    int startNum = Integer.parseInt(args[0]);
	    int endNum = Integer.parseInt(args[1]);
	    int[] foundPrimes = findPrimes(startNum, endNum);
	    for (int i = 0; i < foundPrimes.length; i++) {
		System.out.println(foundPrimes[i]);
	    }
	}
    }

}