/*
CSE 142, Autumn 2007, Marty Stepp
This file can be used to test your solution to a midterm question.
*/

import java.util.*;

public class MidtermTester { 
    public static void main(String[] args) {
        question1();
        question2();
        question3();
        question4();
        question5();
        question6();
    }
    
    public static void question1() {
        System.out.println("Question 1 (expressions):");
        System.out.println(3 + 4 * 5 / 2);
        System.out.println(13 % 5 + 43 % (11 % 3));
        System.out.println(1.5 * 3.0 + 25.0 / 10.0);
        System.out.println(5 / 2 + 123 / 10 / 10.0);
        System.out.println(5 + 2 + "(1 + 1)" + 4 + 2 * 3);
        System.out.println();
    }

    public static void question2() {
        System.out.println("Question 2 (parameters):");
        
        String p = "cause";
        String q = "support";
        String r = "troops";
        String support = "hillary";
        String cause = "rudy";

        troops(p, q, r);
        troops(q, r, p);
        troops(support, p, cause);
        troops(r, "p", support);
        troops(q, "cause", q);
    }

    public static void troops(String r, String p, String q) {
        System.out.println(q + " gave " + r + " to the " + p);
    }

    public static void question3() {
        System.out.println();
        System.out.println("Question 3 (while loop mystery):");
        System.out.println(mystery(2));
        System.out.println(mystery(-1));
        System.out.println(mystery(7));
        System.out.println(mystery(18));
        System.out.println(mystery(43));
        System.out.println();
    }

    public static int mystery(int x) {
        int a = 1;
        int c = 0;
        while (x > 0) {
            a = x % 2;
            if (a == 1) {
                c++;
            }
            x = x / 2;
        }
        return c;
    }
    
    // Can't really test question 4 this way, but here's the code anyway.
    public static void question4() {
        System.out.println("Question 4 (assertions):");
        threeHeads();
        System.out.println();
    }

    // Counts number of "coin tosses" until we get heads 3 times in a row.
    public static int threeHeads() {
        Random rand = new Random();
        int flip = 1;
        int heads = 0;
        int count = 0;
        
        // Point A
        while (heads < 3) {
            // Point B
            flip = rand.nextInt(2);   // flip coin
            if (flip == 0) {  // heads
                heads++;
                // Point C
            } else {          // tails
                // Point D
                heads = 0;
            }
            count++;
        }
        
        // Point E
        return count;
    }

    public static void question5() {
        System.out.println("Question 5 (monthApart):");
        
        System.out.println("Test cases on the exam sheet:");
        testMonthApart( 6,  4,  9, 21);
        testMonthApart( 4,  5,  5, 15);
        testMonthApart( 4, 15,  5, 15);
        testMonthApart( 4, 16,  5, 15);
        testMonthApart( 6, 14,  6,  8);
        testMonthApart( 7,  7,  6,  8);
        testMonthApart( 7,  8,  6,  8);
        testMonthApart(10, 14,  7, 15);

        System.out.println("Test cases we used in grading:");
        System.out.println("Test A (dates are far apart):");
        testMonthApart( 6, 21,  9, 14);
        testMonthApart( 8,  7,  6, 30);
        System.out.println("Tests B and C (1 month apart, days far enough apart):");
        testMonthApart( 4, 15,  5, 16);
        testMonthApart( 5, 15,  4, 14);
        System.out.println("Tests D and E (1 month apart, days too close):");
        testMonthApart( 5,  9,  6,  8);
        testMonthApart( 7,  7,  6,  8);
        System.out.println("Test F (same month):");
        testMonthApart(10,  1, 10, 31);
        System.out.println("Boundary cases (<= vs. <):");
        testMonthApart( 4, 15,  5, 15);
        testMonthApart( 5, 15,  4, 15);
        
        System.out.println("Other test cases:");
        testMonthApart( 8, 19,  9, 21);
        testMonthApart( 8, 21,  9, 21);
        testMonthApart( 8, 22,  9, 21);
        testMonthApart( 9, 11,  9, 21);
        testMonthApart( 9, 29,  9, 21);
        testMonthApart(10, 11,  9, 21);
        testMonthApart(10, 20,  9, 21);
        testMonthApart(10, 21,  9, 21);
        testMonthApart(10, 25,  9, 21);
        testMonthApart(11,  1,  9, 21);
        System.out.println();
    }

    public static void testMonthApart(int m1, int d1, int m2, int d2) {
        System.out.println("monthApart(" + m1 + ", " + d1 + ", " + m2 + ", " + d2 + ") = " + 
            monthApart(m1, d1, m2, d2));
    }
    
    public static boolean monthApart(int m1, int d1, int m2, int d2) {
        // you can replace this code with your solution
        return (m1 < m2 - 1) || (m1 > m2 + 1) || 
               (m1 == m2 - 1 && d1 <= d2) ||
               (m1 == m2 + 1 && d1 >= d2);
    }
    
    public static void question6() {
        System.out.println("Question 6 (sequenceSum):");
        sequenceSum(0.0);
        sequenceSum(1.0);
        sequenceSum(1.5);
        sequenceSum(2.7);
    }

    public static void sequenceSum(double limit) {
        // you can replace this code with your solution
        if (limit >= 1) {
            System.out.print("1");
            int denomenator = 1;
            double sum = 1.0;
            while (sum < limit) {
                denomenator++;
                sum += 1.0 / denomenator;
                System.out.print(" + 1/" + denomenator);
            }
            System.out.println(" = " + sum);
        }
    }
}