import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

/**
 * 
 */

/**
 * @author Donald Yessick
 *
 */
public class Lab16 {
	public static void main(String[] args) {
		// get time in milliseconds since 1970 Jan 1
		long timestamp = System.currentTimeMillis();
		Date now = new Date(); // initialize to current UTC Date/Time
		SimpleDateFormat sdf = new SimpleDateFormat( "EEEE yyyy/MM/dd hh:mm:ss aa zz : zzzzzz" );
		sdf.setTimeZone( TimeZone.getDefault() ); // local time
		String dateString = sdf.format( now );
		System.out.println("milliseconds since 1970 Jan 1="+timestamp);
		System.out.println("Today is "+dateString);
		
		//compareComputeSum();
		
		long timestamp2 = System.currentTimeMillis();
		System.out.println("time elapsed:"+(timestamp2-timestamp)+"ms");
		long timestamp3 = System.currentTimeMillis();
		System.out.println("give or take a few "+(timestamp3-timestamp2+"ms"));
	}
	
	/* loops
		remember this?
			(1 + 2 + .. + n-1 + n) = ((n+1)*n)/2
	*/ 
	
	//TODO:	compute sum here using a for loop
	public static int loopComputeSum_1_to(int n) {
		int sum=0;
		//compute sum here using a for loop
		return sum;
	}
	//TODO: compute sum here using a direct method
	public static int computeSum_1_to(int n) {
		int sum=0;
		//compute sum here using a direct method
		return sum;
	}
	
	//TODO:
	public static int computeLog(int n, int base) {
		//compute log(n, base) using while loop
		//log (n, b) examples
		// n < 1 --> int log (n, b) is undefined 
		// n = 1 --> log (n, b) is 0
		// n = b --> log (n, b) is 1
		// n = b*b --> log (n, b) is 2
		// n = b*b*b --> log (n, b) is 3
		// n = b^b --> log (n, b) is b
		// n = b^n --> log (n, b) is n
		// n = b^k --> log (n, b) is k
		// our job is to find the nearest k such that 
		//b^k <= n
		//b^(k+1) > n
		int log=0;
		return log;
	}
	//TODO:	
	public static int computePower(int base,int n) {
		//compute b^n using while loop
		//examples
		//b^0 =1
		//b^1 = b
		//b^2 = b*b
		int pow = 1;
		return pow;
	}

	//TODO: create a string representing n in base
	public static String convertToBase( int n, int base) {
		return "";
	}
	//TODO: reverse the String (reverse ("abc").equals( "321" );
	public static String reverse( String s ) {
		return "";

	}
	//TODO: reverse the number (reverse (123) == 321
	public static int reverse( int n ) {
		return 0;
	}
	
	
	
	
	/* nothing to do here */
	public static void compareComputeSum() {
		long timestamp1;	
		long timestamp2;	
		long timestamp3;	
		int sum;
		int k;
		timestamp1 = System.currentTimeMillis();	
		//compute sum here using a for loop
		sum=0;
		k = 1;
		while (sum < Integer.MAX_VALUE / k) {
			sum = loopComputeSum_1_to(k);
			k++;
		}
		timestamp2 = System.currentTimeMillis();	
		sum=0;
		k = 1;
		//compute sum here using a direct method
		while (sum < Integer.MAX_VALUE / k) {
			sum = loopComputeSum_1_to(k);
			k++;
		}
		timestamp3 = System.currentTimeMillis();
		k--;
		System.out.println("Computed "+k+" sums");
		System.out.println("time elapsed (looping method):"+(timestamp2-timestamp1)+"ms");
		System.out.println("sum 1..k(looping method):"+loopComputeSum_1_to(k));
		System.out.println("time elapsed (direct method):"+(timestamp3-timestamp2)+"ms");
		System.out.println("sum 1..k(direct method):"+computeSum_1_to(k));
	}
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
}