Making a diamond in recursion

Question

//Making a diamond using recursive methods. The diamond is filled with //whitespace then outlined using / and \.


    //Using java, and has to be using recursive methods.

public static void diaTop(int w){ //this is to make top of diamond
        if(w == 0 )return;
        else System.out.print('/'); //printing left side of diamond
        for(int i = 0; i < w; i++){ //for loop to make spaces
            System.out.print(" ");
        }
            System.out.print('\\'); //printing right side of diamond
            System.out.println();
             diaBot(w-1);
        }

//having a hard time turning the top around so it starts small then enlarges.

    public static void diaBot(int w){ //this is to make bottom of diamond
        if(w == 0 )return;
        else System.out.print('\\');//printing left side of diamond
        for(int i = 0; i < w; i++){ //for loop to make spaces
            System.out.print(" ");
        }
            System.out.print('/'); //printing right side of diamond
            System.out.println();
             diaBot(w-1);
        }


    public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);
        System.out.println("Input width of diamond: ");
        int w = scnr.nextInt(); //getting width of diamond.
        diaTop(w);
        diaBot(w);
    }

/* output
/ \\ \\ / \\ / \\ / \\ / \\ / \\ / \\ / \\ / \\ / */

Answer 1

I worked out a top down solution, not the most fancy bit, but it makes recursive calls, and any professor'd like to see it. The best I can turn in on a Saturday night. The diamond does look a bit dodgy eh, but you can always trim that up the way you like then...

class Diamond {

void draw(int width, int height) {
    if (height - width == height) {
        return;

    } else {
        width -= 2;
        //this bit right here works out the width of spaces
        System.out.print("\n\\");
        for (int i = 0; i < width; i++)
            System.out.print(" ");
        System.out.print("/");

        //This calls the whole thing again, right recursion.
        draw(width, height);
    }
}

void drawTop(int width, int height) {
    if (height - width == height) {
        return;
    } else {

        width -= 2;
       //This does the same as above but in reverse...
        System.out.print("\n/");
        for (int i = 0; i <(height - 2) - width ; i++)
            System.out.print(" ");
        System.out.print("\\");

        //The bit is called here, resursion...
        drawTop(width, height);

    }
}
}

public class Main {

public static void main(String[] args) {

    Diamond diamond = new Diamond();

    //Its not too fancy here, but its right recursion.
    //Go ahead, an add your scanner ere if ya like...
    diamond.drawTop(8,8);
    diamond.draw(8, 8);

}
}