public class MidtermSols {
	public static void main(String args []){
		int limit = 10000;
		int[] primes = getPrimes(limit);
		for (int j=0; j<limit; j++){
		    System.out.println(primes[j]);
		}
		System.out.println(isPalindrome("madam"));
		System.out.println(isPalindrome("maddam"));
		System.out.println(isPrime(15485863));
	}
	public static boolean isPrime(int k){
		if (k <= 1){
			return false;
		}
		else{
			// much more efficient to stop the loop
			// at the square root of k, when k is large
			int limit = (int) Math.sqrt(k);
			for (int j=2; j <= limit; j++){
				if (k % j == 0){
					return false;
				}
			}
			return true;
		}
	}
	public static int[] getPrimes(int n){
		if(n <= 0){
			return new int[0];
		}
		else{
			int primes[] = new int[n];
			int index = 0;
			int k = 2;
			while(index < n){
				if(isPrime(k)){
					primes[index] = k;
					index++;
				}
				k++;
			}
			return primes;
		}
	}
	public static boolean isPalindrome(String s){
		System.out.println("isPalindrome called for " + s);
		int len = s.length();
		if(len <= 1){
			return true;
		}
		else{
			if(s.charAt(0)!= s.charAt(len-1)){
				return false;
			}
			else{
				return isPalindrome(s.substring(1,len-1));
			}
		}
	}
}
// put the answer to Question 3 in a new class that extends Date
class weekCount extends Date{
	public int weeksLater(Date other){
		int days = 0;
		if(this.later(other)){
			Date temp = new Date(other.year, other.month, other.day);
			while(!this.equals(temp)){
				temp.advanceDay();
				days++;
			}
			return days / 7;
		}
		else{
			Date temp = new Date(this.year, this.month, this.day);
			while(!other.equals(temp)){
				temp.advanceDay();
				days++;
			}
			return -days / 7;
		}
	}
}
}