Unit 3 Homework - Kinish S/Rohan J

Question 2

import java.util.*;

public class Quadratic {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);

        double a = sc.nextDouble();
        System.out.println(a);
        double b = sc.nextDouble();
        System.out.println(b);
        double c = sc.nextDouble();
        System.out.println(c);

        double quadratic1 = (-1*b + Math.sqrt(b*b-4*a*c))/2*a;
        double quadratic2 = (-1*b - Math.sqrt(b*b-4*a*c))/2*a;

        System.out.println(quadratic1 + " or " + quadratic2);
    }

}

Quadratic.main(null);

1.0
5.0
1.0
-0.20871215252208009 or -4.7912878474779195

Question 4

import java.util.*;

public class Sign {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.print("Input number - ");
        double input = sc.nextDouble();
        System.out.println(input);

        if (input < 0) {
            System.out.println("Negative");
        }
        else if (input > 0) {
            System.out.println("Positive");
        }
        else {
            System.out.println(0);
        }
        

    }

}

Sign.main(null);

Input number - 25.0
Positive

Question 6

import java.util.*;

public class Round {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.print("Input number - ");
        double input1 = sc.nextDouble();
        System.out.println(input1);

        System.out.print("Input number - ");
        double input2 = sc.nextDouble();
        System.out.println(input2);

        input1 = Math.round(input1 * Math.pow(10, 3)) / Math.pow(10, 3);
        input2 = Math.round(input2 * Math.pow(10, 3)) / Math.pow(10, 3);

        if (input1 == input2) {
            System.out.println("They are the same");
        }
        else {
            System.out.println("They are different");
        }
        

    }

}

Round.main(null);

Input number - 25.586
Input number - 25.589
They are different

Question 8

import java.util.*;

public class Letter {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.print("Input character - ");
        String input1 = sc.next();
        System.out.println(input1);


        if (input1.equals("a") || input1.equals("e") || input1.equals("i") || input1.equals("o") || input1.equals("u") || input1.equals("y")) {
            System.out.println("Character is a vowel");
        }
        else {
            System.out.println("Character is a consonant");
        }
        

    }

}

Letter.main(null);

Input character - a
Character is a vowel

Question 10

public class Natural {

    public static void main (String[] args) {


        System.out.print("The first 10 natural numbers :");
        System.out.println(" ");

        for(int num = 1; num < 11; num++) {
            System.out.println("Enter")
            System.out.println(num);
            int input = sc.nextInt();
        }
        

    }
}

Natural.main(null);

The first 10 natural numbers : 
1
2
3
4
5
6
7
8
9
10

Question 12

import java.util.*;

public class Mean {

    public static void main (String[] args) {

        int n=0;
        int s=0;
        int average = 0;

        
        System.out.println("Input number :");

        for (int i = 0; i < 5; i++) {
            Scanner sc = new Scanner(System.in);
            n = sc.nextInt();
            System.out.println(n);
            s += n;
        }

        average = s/5;
        System.out.println("Sum is " + s);
        System.out.println("Average is " + average);
        

    }
}

Mean.main(null);

Input number :
1
2
3
4
5
Sum is 15
Average is 3

Question 14

import java.util.*;

public class Multiplication {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.println("Input number :");
        int input = sc.nextInt();
        
        int product = 0;

        for (int i = 0; i < 6; i++) {
            product = input * i;
            System.out.println(input + "*" + i + "=" + product);
        }        

    }
}

Multiplication.main(null);

Input number :
5*0=0
5*1=5
5*2=10
5*3=15
5*4=20
5*5=25

Question 16

import java.util.*;

public class Pyramid {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.println("Enter input for number of rows");
        int input = sc.nextInt();
        

        for (int i = 0; i < input; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print(j);
            }

            System.out.println(" ");
        }        

    }
}

Pyramid.main(null);

Enter input for number of rows
 
1 
12 
123 
1234 
12345 
123456 
1234567 
12345678 
123456789 

Question 18

import java.util.*;

public class Triangle {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.println("Enter input for number of rows");
        int input = sc.nextInt();
        
        int k = 1;

        for (int i = 1; i < input; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print(k++);
            }
            System.out.println(" ");
        }        

    }
}

Triangle.main(null);

Enter input for number of rows
1 
23 
456 
78910 

Question 20

import java.util.*;

public class Triangle2 {

    public static void main (String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.println("Enter input for number of rows");
        int input = sc.nextInt();
        
        int k = 1;

        for (int i = 1; i < input; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print(k++);
                System.out.print(" ");
            }
            System.out.println(" ");
        }        

    }
}

Triangle2.main(null);

Enter input for number of rows
1  
2 3  
4 5 6  
7 8 9 10  
11 12 13 14 15  

2019 FRQ 1 A

public static int numberOfLeapYears(int year1, int year2) {
    int count = 0;
    for (int i = year1; i <= year2; i++) {
      // add to count if year is leap year
      if (isLeapYear(i)) count++;
    }
    return count;
  }

2019 FRQ 1 B

public static int dayOfWeek(int month, int day, int year) {
  int day = firstDayOfYear(year) + dayOfYear(month, day, year) - 1;
  // only 7 days in a week
  return day % 7;
}