ch3

import java.util.Scanner;

public class Temperature {

    public static void main (String[] args) {
        
        Scanner in = new Scanner(System.in);
        
        System.out.print("Enter a temperature in celsius: ");
        double cTemp = in.nextInt();
        double fTemp = cTemp * 9.0 / 5 + 32;
        System.out.println(cTemp + " c = " + fTemp + " F");
        System.out.printf("%.1f c = %.1f F", cTemp, fTemp);
        
    }
}

import java.util.Scanner;

public class ConvertTime {
    
    public static void main (String[] args) {
        
        //CONSTANTS
        final double SECONDS_IN_HOUR = 3600;
        final double SECONDS_IN_MINUTE = 60;
        
        //READ INPUT
        Scanner in = new Scanner(System.in);
        System.out.print("Enter an amount of seconds: ");
        int originalSeconds = in.nextInt();
        
        //TIME CALCULATE
        int seconds = originalSeconds;
        int hours   = seconds / SECONDS_IN_HOUR;   //How many hours are there?
        seconds     = seconds % SECONDS_IN_HOUR;   //How many seconds are left over?
        int minutes = seconds / SECONDS_IN_MINUTE; //How many minutes are there?
        seconds     = seconds % SECONDS_IN_MINUTE; //How many seconds are left over after that?
    
        //OUTPUT
        System.out.println(originalSeconds + " seconds = " + hours + " hours, " + minutes + " minutes, and " + seconds + " seconds.");
        System.out.printf("%d seconds = %d hours, %d minutes, and %d seconds.", originalSeconds, hours, minutes, seconds);                   
    }
}

import java.util.Scanner;
import java.util.Random;

public class GuessMyNumber {
    
    public static void main (String[] args) {
        
        // pick a random number
        Random random = new Random();
        int randomNumber = random.nextInt(100) + 1;
        
        // Get input
        System.out.println("I'm thinking of a number between 1 and 100");
        System.out.println("(including both). Can you guess what it is?");
        System.out.print("Type a number: ");
        Scanner in = new Scanner(System.in);
        int guess = in.nextInt();
        
        // Output
        System.out.println("Your guess is: " + guess);
        System.out.println("The number I was thinking of is: " + randomNumber);
        System.out.println("You were off by: " + (randomNumber - guess));    
    }
}