1.
Expression                                     Value
8 + 5 * 3 / 2                                   15
1.5 * 4 * 7 / 8 + 3.4                           8.65
73 % 10 - 6 % 10 + 28 % 3                       -2
4 + 1 + 9 + "." + (-3 + 10) + 11 / 3            "14.73"
3 / 14 / 7 / (1.0 * 2) + 10 / 6                 1.0



2.
happy and pumpkin were orange!
orange and happy were pumpkin!
orange and sleepy were y!
pumpkin and x were green!
green and pumpkin were vampire!



3.
Method Call                                    Returns
mystery(2, 9)                                  0
mystery(5, 1)                                  6
mystery(38, 5)                                 119
mystery(5, 5)                                  0
mystery(40, 10)                                57



4.
                 next < 0                 y > z                 y == 0
        +---------------------+---------------------+---------------------+
Point A | sometimes           | never               | always              |
        +---------------------+---------------------+---------------------+
Point B | never               | sometimes           | sometimes           |
        +---------------------+---------------------+---------------------+
Point C | never               | always              | never               |
        +---------------------+---------------------+---------------------+
Point D | sometimes           | sometimes           | never               |
        +---------------------+---------------------+---------------------+
Point E | always              | sometimes           | sometimes           |
        +---------------------+---------------------+---------------------+



5.  Five solutions are shown.

public static boolean enoughTimeForLunch(
        int h1, int m1, int h2, int m2) {
    if (h1 > h2) {    
        return false;
    } else if (h1 == h2) {
        return m2 - m1 >= 45;
    } else if (h1 == h2 - 1) {
        return 60 + m2 - m1 >= 45;
    } else {                     
        return true;
    }
}	public static boolean enoughTimeForLunch(
        int h1, int m1, int h2, int m2) {
    if (h2 > h1 + 1) {
        return true;
    } else if (h2 == h1 && m1 + 45 <= m2) {
        return true;
    } else if (h2 == h1 + 1 && m1 - 15 <= m2) {
        return true;
    } else {
        return false;
    }
}

public static boolean enoughTimeForLunch(int h1, int m1, int h2, int m2) {
    if (h1 > h2) {
        return false;
    } else if (h1 == h2) {         // same hour
        if (m1 + 45 <= m2) {       //   must be >= 45 min apart
            return true;
        } else {
            return false;
        }
    } else if (h2 == h1 + 1) {     // h1 is just before h2
        if (m1 - 15 <= m2) {       //   must be >= -15 min apart
            return true;
        } else {
            return false;
        }
    } else {                       // time 1 is > 1 hour before time 2
        return true;
    }
}

public static boolean enoughTimeForLunch(int h1, int m1, int h2, int m2) {
    if ((h1 == h2 && m1 + 45 <= m2) || (h2 == h1 + 1 && m1 - 15 <= m2) || (h1 < h2 - 1)) {
        return true;
    } else {
        return false;
    }
}

public static boolean enoughTimeForLunch(int h1, int m1, int h2, int m2) {
    return 60 * h1 + m1 + 45 <= 60 * h2 + m2;
}



6.  One solution is shown.

public static void threeHeads() {
    Random r = new Random();
    int numHeads = 0;
    
    while (numHeads < 3) {
        int flip = r.nextInt(2); // flip coin
        if (flip == 0) { // heads
            numHeads++;
            System.out.print("H ");
        } else {
            numHeads = 0;
            System.out.print("T ");
        }
    }
    System.out.println();
    System.out.println("Three heads in a row!");
}



7.  Two solutions are shown.

public static int numTWords(String s) {
    int count = 0;
    int i = 0;
    while (i < s.length()) {
        while (i < s.length() && s.charAt(i) == ' ') {  // skip over whitespace
            i++;
        }
        if (i < s.length()) {
            if (s.charAt(i) == 't' || s.charAt(i) == 'T') {
                count++;
            }
            while (i < s.length() && s.charAt(i) != ' ') {  // skip until find next whitespace
                i++;
            }
        }
    }
    return count;
}

public static int numTWords(String s) {
    s = s.toLowerCase();
    int count = 0;
    if (s.charAt(0) == 't') {
        count++;
    }
    for (int i = 0; i < s.length() - 1; i++ ) {
        if (s.charAt(i) == ' ' && s.charAt(i + 1) == 't') {
            count++;
        }
    }
    return count;
}