1. arrays/print

public static void print(int[] a) {
    for (int i = 0; i <a.length; i++) {
        System.out.println("element " + "[" + i + "]" + " is " +  a[i]);
    
    }
    
}

2. arrays/maxValue

public static int maxValue(int[] a) {
    int max = Integer.MIN_VALUE;
    for (int i = 0; i <a.length; i++) {
        if (a[i] > max) {
            max = a[i];
        }
    }
    return max;
}

3. arrays.squareArray

int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int[] squares = new int[array.length];
for (int i = 0; i < array.length; i++) {
    squares[i] = array[i] * array[i];
}

4. console output/printProgram

public class PrintProgram{
    
    //static String s = "public class public class Hello {";
    
    public static void main(String[] args) {
        
        System.out.println("public class Hello {");
        System.out.println("    public static void main(String[] args) {");
        System.out.println("        System.out.println(\"Hello, world!\");");
        System.out.println("    }");
        System.out.println("}");      
       
    }
}

5. consile output/calculate line

import java.util.Scanner;
public class CalculateLine {
    public static void main (String [] args) {
        int x;
        int y;
        Scanner odczyt =  new Scanner(System.in);
        System.out.println("This program calculates y coordinates for a line.");
        System.out.print("Enter slope (m): ");
        int slope = odczyt.nextInt();
        System.out.print("Enter intercept (b): ");
        int intercept = odczyt.nextInt();
        System.out.print("Enter x: ");
        x = odczyt.nextInt();
        while (x != -1) {
            y = slope*x + intercept;
            System.out.println("f("+ x +") = " + y);
            System.out.print("Enter x: ");
            x = odczyt.nextInt();
        } 
    }
}

6. cons out/evensumMax

import java.util.Scanner;

public static void evenSum() {
    int quantity;
    int integer;
    int max = -1000000;
    int evenSum = 0;
    Scanner odczyt = new Scanner(System.in);
    System.out.print("how many integers? ");
    quantity = odczyt.nextInt();
    for (int i = 0 ; i < quantity; i++) {
        System.out.print("next integer? ");
        integer = odczyt.nextInt();
        
        if (integer%2 == 0) {
            evenSum += integer;
            if (integer > max) {
                max = integer;
            }
        }
        
    }
    System.out.println("even sum = " + evenSum);
    System.out.println("even max = " + max);
}


7. cons out/FearTheTree

System.out.println("\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\");
System.out.println("|| FEAR THE TREE! ||");
System.out.println("////////////////////");


8. cons out/inches to cm

import java.util.Scanner;
import java.text.*;

public class InchesToCentimeters{
    static public double round(double d, int ic) {
        java.text.NumberFormat nf = java.text.NumberFormat.getInstance();
        nf.setMaximumFractionDigits(ic);
        nf.setMinimumFractionDigits(ic);
    return Double.parseDouble((nf.format(d)).replaceAll(",", ".").replaceAll(" ", "") );
    }
    public static void main(String[] args) {
        System.out.println("This program converts feet and inches to centimeters.");
        int Feet;
        int Inches;
        Double Feet_Inches;
        Double Suma;
        double Centimeters, Cm_Format;
        Scanner sc = new Scanner(System.in);
        
        System.out.print("Enter number of feet: ");
        Feet = sc.nextInt();
        //int feet = Integer.parseInt(Feet);
       
        System.out.print("Enter number of inches: ");
        Inches = sc.nextInt();
        //Double inches = Double.parseDouble(Inches);
        
        Feet_Inches = Inches / 12.00 ;
        Suma = Feet + Feet_Inches;
        //Double suma = Double.parseDouble(Suma);
 
        Centimeters = Suma * 30.48;
        
        
        System.out.print(Feet + "ft " + Inches + "in " + "= " + round(Centimeters,2) + "cm");
    }
}

9. cons/out/number square

public static void numberSquare(int min, int max) {
    int range = max - min + 1;
    for (int i = 0; i < range; i ++) {
        for(int j = 0; j < range; j++ ) {
            
            System.out.print( (i + j ) % (range) + min );
        }
        System.out.println();
    }
    
}


10. cons out/print triangle

public static void printTriangle() {
    String newline = System.lineSeparator();
    for(int i=0;i<=5; i++) {
        for (int j=0;j<=i;j++){
            System.out.print("#");
        }
      System.out.println();
    }
}

11. cons out/stanford vs call

import java.util.Scanner;
public class StanfordVsCal{
    public static void main(String[] args) {
        int Stanford;
        int Cal;
        Scanner odczyt = new Scanner(System.in);
        System.out.print("Stanford: How many points did they score? ");
        Stanford = odczyt.nextInt();
        System.out.print("Cal: How many points did they score? ");
        Cal = odczyt.nextInt();
        if (Stanford > Cal) {
            System.out.println("Stanford won!");
        }else {
            System.out.println("Cal won!");
        }

    }
}


12. expressions / digit expressions

10s place: number%100/10
100s place: number%1000/100

13. expressions/displacement

import java.lang.Math;

double s0 = 12.0;
double v0 = 3.5;
double a = 9.8;
double t = 10.0;
double s = s0 + v0*t + 0.5 * a * Math.pow(10,2);
System.out.print(s);


14. expressions/printMaxMin

	46,36,23,13
    
15.expresions/times operator

    double y;
    y = x*(x*(x*(12.3*x - 9.1) + 19.3) - 4.6) + 34.2;
    System.out.print(y);
    
16. expressions/valuesOfABC

	6,9,16
    
17. expressions/valuesOfIJK

	4,2,1
    
18. loops/biggerAndSmaller

import java.util.Scanner;

public class BiggestAndSmallest {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.print("Number of numbers? ");
        int n = sc.nextInt();
        int biggest = -100000000;
        int smallest = 10000000;
        for (int i = 1; i <=n; i++) {
            System.out.print("Number " + i +": ");
            int number = sc.nextInt();
            if (number>biggest) {
                biggest = number;
            }
            if (number < smallest) {
                smallest = number;
            }
        }
        
        System.out.println("Biggest = " + biggest);
        System.out.println("Smallest = " + smallest);
    }
}

19. loops/ComputeSumOfDigits

import java.util.Scanner;

public class ComputeSumOfDigits {
    public static void main(String[] args){
        int integer, Int;
        int suma = 0;
        
        
        
        Scanner odczyt = new Scanner(System.in);
        System.out.print("Type an integer: ");
        integer = odczyt.nextInt();
        int length = (int)(Math.log10(integer)+1);
       
        
        while (integer > 0) {
            
            suma += integer%10;
            integer = integer/10;
            //System.out.println("Digit sum is: ");
           
        }
        System.out.println("Digit sum is " + suma);
        
    }
}

20. loops/FizzBuzz

import java.util.Scanner;

public class FizzBuzz {
    public static void main(String[] args) {
        int max;
        double a;
        Scanner odczyt = new Scanner(System.in);
        System.out.print("Max value? ");
        max = odczyt.nextInt();
        a = max / 20.0;
        for (int i = 0; i < a; i++) {
            for (int j = 0; j < 20; j++) {
                if ((i*20 + j + 1)%15==0) {
                    System.out.print("FizzBuzz ");
                } else if ((i*20 + j + 1)%5==0) {
                    System.out.print("Buzz ");
                }else if ((i*20 + j + 1)%3==0) {
                    System.out.print("Fizz ");
                } else {
                    System.out.print(i*20 + j + 1);
                    System.out.print(" ");
                }
                
                
                if ((i*20 + j + 1)==max ) {
                    break;
                }
            }
            System.out.println();
        }
    }   
} 

21. loops/numberLoops1

for (int i = 1; i<=5; i++){
    for (int j = 1; j <=i; j++) {
        print(i);
    }
    println();
}

22. loops/numberLoops2

for (int i = 1; i <= 5; i++) {
    for (int j = 1; j <= 5; j ++) {
        if (j < 6-i){
            print(".");
        }
        else {
            print(i);
        }
    }
    println();
}

23. loops/numberLoops3

for (int i = 1; i <= 5; i++){
    for (int j = 5; j >= 1; j--) {
        if (i == j) {
            print(i);
        }
        else {
            print(".");
        }
    }
    println();
}


24. loops/numberSquare

import java.util.Scanner;


public class NumberSquare{   
    public static void main(String[] args) {
        int min, max;
        Scanner odczyt = new Scanner(System.in);
        
        System.out.print("Min? ");
        min = odczyt.nextInt();
        
        System.out.print("Max? ");
        max = odczyt.nextInt();
        int range = max - min + 1;
        
        for (int i = 0; i < range; i ++) {
            for(int j = 0; j < range; j++ ) {
                System.out.print( (i + j ) % (range) + min );
            }
            System.out.println();
        }
    }
}


25. loops/sentinelSum

import java.util.Scanner;

public class SentinelSum {
    public static void main(String[] args) {
        int number, suma=1;
        Scanner sc = new Scanner(System.in);  
        do {
            System.out.print("Type a number: ");
            number = sc.nextInt();
            suma += number;
        } while (number != -1);     
        System.out.print("Sum is " + suma); 
    }
}


26. parameters/boxOfStars

public static void boxOfStars(int width, int hight){
    for (int i = 0; i < hight; i++) {
        for (int j = 0; j < width; j++) {
            if (i == 0) {
                System.out.print("*");
            } else if ((i > 0 && i < hight - 1) && (j == 0 || j == width -1)) {
                System.out.print("*");
            } else if ( i == hight -1) {
                System.out.print("*");
            }else {
                System.out.print(" ");
            }
        }
        System.out.println();
    } 
}

27. parameters/countDigits

public static int countDigits(int Number) {
    String number = Integer.toString(Number);
    if (Number > 0) {
        return number.length();
    } else{
        return number.length() - 1;
    }   
}


28. parameters/investment

import java.util.Scanner;


public class Investment {
    public static Double FinalAmount (Double PV, double r, int n) {
        Double FV;
        FV = PV*Math.pow(1+r, n);
        return FV;
    }
    
    public static Double Profit(Double PV, Double FV) {
        return FV - PV;
    }  
    
    public static double CalcPercent(double PV, double Profit) {
        
        return (Profit-PV)  / PV* 100.00;
    }
    
    public static String Category(double Percent){
       
        if (Percent >= 0 && Percent < 10) {
            return "weak";
        }else if (Percent >= 10 && Percent < 50) {
            return "medium";
        } else {
            return "strong";
        }
    }
    
    public static void Oblicz(String inwestor, Scanner odczyt) {
        Double PV,r, Profit;
        int n;
//        Scanner odczyt = new Scanner(System.in);
        
        System.out.println("Investor #" + inwestor + ":");
        
        System.out.print("Initial amount? ");
        PV = odczyt.nextDouble();
        
        System.out.print("Interest rate%? ");
        r = odczyt.nextDouble();
        
        System.out.print("Num. of months? ");
        n = odczyt.nextInt();
        
        Double finalAmount = FinalAmount(PV, r, n);
        System.out.printf("Final amount = $%.2f\n", finalAmount);
        
        Double profit = Profit(PV, finalAmount);
        Double Percent = CalcPercent(PV, finalAmount);
        
        System.out.printf("Profit = $%.2f (%.0f%%)\n", profit, Percent);
        System.out.println(Category(Percent));
    }
    
    public static void main(String[] args) {
        Scanner odczyt = new Scanner(System.in);
        Oblicz("1", odczyt);
        System.out.println();
        Oblicz("2", odczyt);
        System.out.println();
        System.out.println("Have a nice day!");
        
    }
    
}


29. parameters/printpay

public static void printPay(Double Salary, int Hours) {
    Double Earnings;
    int Difference;
    if (Hours <= 8) {
        Earnings = Salary * Hours;
    } else {
        Difference = Hours - 8;
        Earnings = 1.5*Salary *Difference + 8*Salary;
    }
    System.out.println("Hours worked: " + Hours);
    System.out.printf("Pay earned: $" + String.format( "%.2f", Earnings ) );
} 



30. parameters/triangle

public static void triangle(int size){
    for (int i = 0; i < size; i ++){
        for (int j = 1; j <= size; j++) {
            if (j < size  - i) {
                System.out.print(" ");
            }else {
                System.out.print("*");
            }
        }
        System.out.println();
    }
    
    
}


31. parameters/getDaysMonth

public static int getDaysInMonth(int Month) {
    int [] Days = {31,28,31,30,31,30,31,31,30,31,30,31};
        
    return Days[Month - 1];
}