Question

How to replace elements in a 2D array?

Okay so for my program, I am trying to create a fish tank. My program is to generate 4 different FISH: ><))'> in a tank of tilde (~) characters. The tank is a 2D array of 8 rows and 32 columns so it would look like ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ for one of the eight rows (before I generate the random positions of the fish in the rank). Then one row could look like ~~~~~~~~~~><))'>~~~~~~~~~~~~~~~~ after I generate random positions for my fish. It should also hide characters of the fishes body if it is more to the left like such )'>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ where there is only three parts of the fish, 2 body characters and the head character.The random position coordinate I have generated for each of the four fishes starts on the head of the fish (>) which means I have been able to successfully generate four > in the tank, which looks like ~~~~~~~~~~~~~~~~>~~~~~~~~~~~~~~~ when ran. But my problem is how I can get the rest of the fishes body after the head. I know I am going to be working backwards from the > character and replace the tilde characters with characters from the fishes body. I don't need the direct answer, rather some steps that would explain it and some suggestions. It would be a big help. Here is some of the code below.

import java.util.Random;

public class Main {

   public static void main(String[] args) {

       char [][] tilde = new char [8][32];

       fillTank(tilde, '~');

       int fish [][] = generateRandomPositions(4, 8, 32);

       for (int i = 0; i < fish.length; ++i) {

           placeFishInTank(tilde, fish[i][0], fish[i][1]); // METHOD I AM ON...

       }

       renderTank(tilde);

   }

public static void placeFishInTank(char [][] positionInTank, int x, int y) //METHOD TO PLACE THE HEAD AND BODY

   {

       positionInTank[x][y] = '>'; //PLACING THE HEAD

  

   //   for (int i = 0; i < positionInTank.length; i++) {

   //       for (int j = 0; i < positionInTank[x].length; j++)

   //           if (positionInTank[][] >= 0) {

   //               String.charAt(i, j);

   //           }

   //   }

//OR I WAS THINKING OF DOING SOMETHING LIKE

       //if (!positionInTank[row].length - 1 = 0) {

       //add on next character '\''

   //   }

      

       //if (!positionInTank[row] - 2 = 0) {

      //add on next character ')'

   //   }

      

       //if (!positionInTank[row] - 3 = 0) {

       //add on next character ')'

   //   }

      

       //if (!positionInTank[row] - 4 = 0) {

       //add on next character '<'

   //   }

      

       //if (!positionInTank[row] - 5 = 0) {

       //add on next character '>'

   //   }

      

   }

Answer 1

set fish[] = {> ,< ,), ), ', >} // place fish characters in an array

set head = 5 // head as the last index

loop if x > 0 or head > 0 // loop till reached end of the maze i.e. x > 0 or complete fish is drawn i.e. head > 0

start

place fish[head] at position[x, y]

head = head - 1;

x = x - 1;

end