SieveGraphicalSimulation

import java.util.Arrays;
import java.util.Scanner;
import java.awt.*;

public class SieveGraphicalSimulation {

    public static final Color BLACK      = Color.BLACK;
    public static final Color BLUE       = Color.BLUE;
    public static final Color CYAN       = Color.CYAN;
    public static final Color DARK_GRAY  = Color.DARK_GRAY;
    public static final Color GRAY       = Color.GRAY;
    public static final Color GREEN      = Color.GREEN;
    public static final Color LIGHT_GRAY = Color.LIGHT_GRAY;
    public static final Color MAGENTA    = Color.MAGENTA;
    public static final Color ORANGE     = Color.ORANGE;
    public static final Color PINK       = Color.PINK;
    public static final Color RED        = Color.RED;
    public static final Color WHITE      = Color.WHITE;
    public static final Color YELLOW     = Color.YELLOW;
    public static final Color[] colours = {CYAN,MAGENTA,ORANGE,PINK,RED,YELLOW};

    public static void main(String[] args) {
        try{
            Scanner scanner = new Scanner(System.in);
            System.out.println( "Sieve of Eratosthenes (Prime Finder)" + "\nPlease enter the maximum number you wish to see up until?" );
            int input = scanner.nextInt();
            int counter = 0;
            while(counter==0){
                if (input<=1){
                    System.err.println("Error, please enter positive whole numbers only please (from 2 onwards).");
                    input = scanner.nextInt();
                }
                else{
                    counter=1;
                }
            }
            int[] numbers = numbers(input);
            StdDraw.setCanvasSize(800, 750);
            double scale =(double)input/1000;
            StdDraw.setXscale(0.0,1.3);
            StdDraw.setYscale(0.0,1.0);
            boolean[] multiples = markOfMultiples(numbers,input);
            int newSize = input-1;
            int[] output = printSquares(multiples,numbers,input,newSize);
            StdDraw.show(1500);
            int[] newArray = colourMultiples(multiples,input,numbers,newSize);
            scanner.close();
        }
        catch(java.util.InputMismatchException exception)
        {
            System.err.println("Error, please enter whole numbers only."
                    + "\nPlease restart the program and try again.");
        }
        catch(NullPointerException exception2)
        {
            System.err.println("Error, please enter whole numbers only."
                    + "\nPlease restart the program and try again.");
        }
    }
    public static int[] numbers (int input){ //creates the initial array of numbers, from 2 until the user input
        int[] multiples = new int[input];
        int n = 2;
        int size = input-1;
        for (int i=0;i<size;i++){
            multiples[i] = n;
            n++;
        }
        return multiples;
    }
    public static int[] printSquares (boolean[] multiples, int[]numbers, int input, int newSize){
        int squareMaker = (int)Math.sqrt(input);
        double x = 0.15;
        double y = 0.95;
        double r = 0.05;
        int counter = 0;
        for(int i=0;i<newSize;i++){
            int number = numbers[i];
            if (i==squareMaker-1 || counter == squareMaker){
                counter = 0;
                x = 0.045;
                y=(y-0.105);
            }
            double Scale = input/1000;
            StdDraw.setXscale(0.0,1.3);
            StdDraw.setYscale(0.0,1.0);
            String numberOutput = Integer.toString(number);
            StdDraw.setPenColor(LIGHT_GRAY);
            StdDraw.filledSquare(x, y, r);
            StdDraw.setPenColor(BLACK);
            Font textFont = new Font("SansSerif", Font.PLAIN, 10);
            StdDraw.setFont(textFont);
            StdDraw.text(x,y,numberOutput);
            counter++;
            x=x+(.105);
        }
        return null;
    }

    public static boolean[] markOfMultiples (int[] numbers, int input) { //creates a boolean array that marks multiples of a base prime with 'false'
        boolean[] primeFinder = new boolean[input];
        Arrays.fill(primeFinder, Boolean.TRUE);
        int size = input - 1;
        for(int i=0;i<size;i++){
            int number = numbers[i];
            for(int p=1;p<size;p++){
                int divisor = numbers[p];
                if (divisor!=number){
                    if (divisor%number==0){
                        primeFinder[p] = false;     //sets the position (matching the numbers array) in the boolean array to false
                    }
                }
            }
        }
        return primeFinder;
    }
    public static int[] colourMultiples (boolean[] multiples, int input, int[] numbers, int newSize){
        int squareMaker = (int)Math.sqrt(input);
        int[] primeNumbers = new int[newSize];
        double xIncrease = 0.15;
        double yIncrease = 0.95;
        int ovCounter = 0;
        Font primeOutput = new Font("SansSerif", Font.BOLD, 20);
        Font textFont = new Font("SansSerif", Font.PLAIN, 15);
        StdDraw.setPenColor(BLACK);
        StdDraw.setFont(primeOutput);
        double fontX = (squareMaker*0.105);
        double fontY = 0.95;
        StdDraw.text(fontX+0.15,fontY,"Prime Numbers:");
        int t=100;
        for (int i = 0; i< newSize;i++){
            double x = 0.15;
            double y = 0.95;
            double r = 0.05;
            int counter = 0;
            if (i==squareMaker-1 || ovCounter == squareMaker){
                ovCounter = 0;
                xIncrease = 0.045;
                yIncrease=(yIncrease-0.105);
                fontX = (squareMaker*0.105);
                fontY -= 0.05;
            }
            int number = numbers[i];
            if(multiples[i]==true){
                StdDraw.setPenColor(GREEN);
                StdDraw.filledSquare(xIncrease, yIncrease, r);
                String numberOutput = Integer.toString(number);
                StdDraw.setFont(textFont);
                StdDraw.setPenColor(BLACK);
                StdDraw.text(fontX+0.05,(i>=0||i<=squareMaker)?(fontY-0.05):fontY,numberOutput+" ");
                StdDraw.text(xIncrease,yIncrease,numberOutput);
                for (int p = 0; p< newSize;p++){
                    StdDraw.show(t);
                    int divisor = numbers[p];
                    if (p==squareMaker-1 || counter == squareMaker){
                        counter = 0;
                        x = 0.045;
                        y=(y-0.105);
                    }
                    if (divisor!=number){
                        if (divisor%number==0){
                            StdDraw.setPenColor(RED);
                            StdDraw.filledSquare(x, y, r);
                            String divisorOutput = Integer.toString(divisor);
                            StdDraw.setPenColor(BLACK);
                            StdDraw.setFont(textFont);
                            StdDraw.text(x,y,divisorOutput);
                        }
                    }
                    counter++;
                    x=x+(.105);
                }
                if(t>10){
                    t=t-10;
                }
                x = 0.15;
                y = 0.95;
                r = 0.05;
                counter=0;
                StdDraw.show(500);
                for (int p = 0; p< newSize;p++){
                    int divisor = numbers[p];
                    if (p==squareMaker-1 || counter == squareMaker){
                        counter = 0;
                        x = 0.045;
                        y=(y-0.105);
                    }
                    if (divisor!=number){
                        if (divisor%number==0){
                            StdDraw.setPenColor(PINK);
                            StdDraw.filledSquare(x, y, r);
                            String divisorOutput = Integer.toString(divisor);
                            StdDraw.setPenColor(BLACK);
                            StdDraw.setFont(textFont);
                            StdDraw.text(x,y,divisorOutput);
                        }
                    }
                    counter++;
                    x=x+(.105);
                }
                fontX += 0.05;
            }
            StdDraw.show(5*t);
            ovCounter++;
            xIncrease=xIncrease+(.105);
        }
        return primeNumbers;
    }
}