Printing string in rows and column pattern Java

Question

i\'m just created a java project to print string that is given in rows and column just like matrix. Here\'s the output that i just made:

h e l l o 
_ w o r l 
d _         


        

Answer 1

Basically, you move through the string from start to end, but treat the stringbuffer as an array. You#ll also need to to keep track of your direction (dx,dy) and where your bounds are.

The following code will produce:

hello
beau 
 l.tw
sufio
i dlr

given the input "hello world is beautiful"

public class Main {

    public static void main(String[] args) {
        String text ="hello world is beautiful";
        int len = text.length();
        double sideLength = Math.sqrt( len );
        int width = 0;
        int height = 0;

        // check if it's a square
        if ( sideLength > (int) sideLength) {
            // nope... it#s a rectangle
            width = (int) sideLength +1;
            height = (int) Math.ceil((double)len / (double)width);
        } else {
            // square
            width = (int) sideLength;
            height = (int) sideLength;
        }

        // create a buffer for the spiral
        StringBuffer buf = new StringBuffer( width * height );
        buf.setLength( width * height );
        // clear it.
        for (int a=0; a < buf.length(); a++ ) {
            buf.setCharAt(a, '.');
        }
        

        int dstX = 0;
        int dstY = 0;
        int curWidth =  width;
        int curHeight = height;
        int startX = 0;
        int startY = 0;
        int dx = 1;
        int dy = 0;
        // go through the string, char by char
        for (int srcPos =0; srcPos < len; srcPos++) {
            buf.setCharAt( dstX + dstY * width, text.charAt( srcPos ));

            // move cursor
            dstX += dx;
            dstY += dy;

            // check for bounds
            if ( dstX == curWidth-1 && dx > 0) {
                // end of line while going right, need to go down
                dx = 0;
                dy = 1;
                // also, reduce width
                curWidth--;
                startY++;
            } else if (dstY == curHeight-1 && dy > 0) {
                // end of column while going down, need to go left
                dx = -1;
                dy = 0;

                // also, reduce height
                curHeight--;
            } else if (dstX == startX && dx < 0) {
                // hit left border while going left, need to go up
                dx = 0;
                dy = -1;
                // also, increase startX
                startX++;
            } else if (dstY == startY && dy < 0) {
                // hit top border, while going up, need to go right
                dx = 1;
                dy = 0;
                // also, increase startY
                startY++;
            }
            
        }


        // display string
        for (int line = 0; line < height; line++) {
            System.out.println( buf.substring( line* width, line*width +width) );
        }
    }
}