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二维阵列中的寻路算法

更新时间:2023-02-26 16:28:47

在在以下代码中,我删除了对演示所请求算法并非必不可少的所有内容。该代码确实包含一些用于测试的数据。

我认为发布 mcve 对于质量问题和解决方案非常有帮助。答案。太多的信息就太少了。

代码按要求搜索路径。请注意,它不会搜索任何特定的路径属性(例如最短路径或最长路径)。

另外,编写的代码将查找一条路径。他们可能更多。

我想您需要研究代码以使其适应您的需求,对其进行进一步测试,并希望对其进行改进。

In the following code, I removed everything which is not essential to demonstrate the requested algorithm. The code does include some data for testing.
I think posting a mcve is very helpful for quality questions and answers. Too much information is as bad as too little.
The code searches a path as requested. Please note that it does not search for any particular path property (like shortest ot longest path).
Also, the code as written looks for one path. Their may be more.
I assume you'll need to study the code to adapt it to your needs, further test it, and hopefully improve it.

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Stack;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;


public final class Pha extends JFrame {

    //a collection of cells in the path.
    //each cell represented by [row,col]
    private Stack<int[]>path;

    //a path shorter than min can not surround any cell
    private static final int MIN_PATH_LEGTH = 4;

    //a collection of cells that has been tested
    private ArrayList<int[]>checked;

    //represents the cell where the search starts from
    int[] origin;
    //represents the token of the origin
    Token originToken;

    private static int ROWS = 15;
    private static int COLS = ROWS;
    private static int cellSize = 15;
    private static int canvasWidth = (cellSize * COLS) + (ROWS *4) ;
    private static int canvasHeight = cellSize * ROWS ;
    private static int gridWidth = 1;
    private static int halfGridWidth = gridWidth / 2;

    private static int cellPadding = cellSize / 5;
    private static int symbolSize = cellSize - (cellPadding * 2);
    private static int symbolStrokeWidth = 3;

    private enum Token{
        VIDE, CERCLE_ROUGE, CERCLE_BLEU
    }

    private Token[][] board;
    private final DrawCanvas canvas;

    //used to set different test data
    private static int testNumber = 0;

    public Pha(){

        canvas = new DrawCanvas();
        canvas.setPreferredSize(new Dimension(canvasWidth, canvasHeight));

        Container cp = getContentPane();
        cp.setLayout(new BorderLayout());
        cp.add(canvas, BorderLayout.EAST);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setTitle("Pha par esQmo");
        setVisible(true);

        board = new Token[ROWS][COLS];
        initGame();

        //fill some data for testing
        int[] origin = loadtestData(board);
        findPath(origin);
    }

    private void initGame(){

        for(int ligne = 0; ligne < ROWS; ++ligne){
            for(int colonne = 0; colonne < COLS; ++colonne){
                board[ligne][colonne] = Token.VIDE;
            }
        }
    }
    //search for a path
    private void findPath(int[] origin) {

        //initialize path and checked
        path = new Stack<>();
        this.origin = origin;

        int row = origin[0] , col =  origin[1];

        //represents the token of the origin
        originToken = board[row][col];

        //initialize list of checked items
        checked = new  CellsList();

        boolean found = findPath(row, col);

        if(found) {
            printPath();
        } else {
            System.out.println("No path found");
        }
    }

    //recursive method to find path. a cell is represented by its row, col
    //returns true when path was found
    private boolean findPath(int row, int col) {

        //check if cell has the same token as origin
        if(board[row][col] != originToken) {
            return false;
        }

        int[] cell = new int[] {row, col};

        //check if this cell was tested before to avoid checking again
        if(checked.contains(cell)) {
            return false;
        }

        //get cells neighbors
        CellsList neighbors = getNeighbors(row, col);

        //check if solution found. If path size > min and cell
        //neighbors contain the origin it means that path was found
        if((path.size() > MIN_PATH_LEGTH) && neighbors.contains(origin)  ) {

            path.add(cell);
            return true;
        }

        //add cell to checked
        checked.add(cell);

        //add cell to path
        path.add(cell);

        //if path was not found check cell neighbors
        for(int[] neighbor : neighbors ) {

            boolean found = findPath(neighbor[0],neighbor[1]);
            if(found) {
                return true;
            }
        }

        //path not found
        path.pop(); //remove last element from stack
        return false;
    }

    //return a list of all neighbors of cell row, col
    private CellsList getNeighbors(int  row, int col) {

        CellsList neighbors = new CellsList();

        for (int colNum = col - 1 ; colNum <= (col + 1) ; colNum +=1  ) {

            for (int rowNum = row - 1 ; rowNum <= (row + 1) ; rowNum +=1  ) {

                if(!((colNum == col) && (rowNum == row))) {

                    if(withinGrid (rowNum, colNum )  ) {

                        neighbors.add( new int[] {rowNum, colNum});
                    }
                }
            }
        }

        return neighbors;
    }

    private boolean withinGrid(int colNum, int rowNum) {

        if((colNum < 0) || (rowNum <0) ) {
            return false;
        }
        if((colNum >= COLS) || (rowNum >= ROWS)) {
            return false;
        }
        return true;
    }

    private void printPath() {
        System.out.print("Path : " );
        for(int[] cell : path) {
            System.out.print(Arrays.toString(cell));
        }
        System.out.println("");
    }

    class DrawCanvas extends JPanel{

        @Override
        public void paintComponent(Graphics g){
            super.paintComponent(g);
            setBackground(Color.WHITE);

            g.setColor(Color.BLACK);
            for(int ligne = 1; ligne < ROWS; ++ligne){
                g.fillRoundRect(0, (cellSize * ligne) - halfGridWidth, canvasWidth - 1,
                        gridWidth, gridWidth, gridWidth);
            }
            for(int colonne = 1; colonne < COLS; ++colonne){
                g.fillRoundRect((cellSize * colonne) - halfGridWidth, 0
                        , gridWidth, canvasHeight - 1,
                        gridWidth, gridWidth);
            }


            Graphics2D g2d = (Graphics2D)g;
            g2d.setStroke(new BasicStroke(symbolStrokeWidth,
                    BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
            for(int ligne = 0; ligne < ROWS; ++ligne){
                for(int colonne = 0; colonne < COLS; ++colonne){
                    int x1 = (colonne * cellSize) + cellPadding;
                    int y1 = (ligne * cellSize) + cellPadding;

                    if(board[ligne][colonne] == Token.CERCLE_ROUGE){
                        g2d.setColor(Color.RED);
                        g2d.drawOval(x1, y1, symbolSize, symbolSize);
                        g2d.fillOval(x1, y1, symbolSize, symbolSize);
                    } else
                        if(board[ligne][colonne] == Token.CERCLE_BLEU){
                            int x2 = (colonne * cellSize) + cellPadding;
                            g2d.setColor(Color.BLUE);
                            g2d.drawOval(x1, y1, symbolSize, symbolSize);
                            g2d.fillOval(x2, y1, symbolSize, symbolSize);
                        }
                }
            }
        }
    }

    public static void main(String[] args){

        //set test number. Change values between 0-2 to run different tests
        testNumber = 2;
        SwingUtilities.invokeLater(() -> {
            new Pha();
        });
    }

    //method used for testing only: load test data
    private static int[] loadtestData(Token[][] board) {

        switch (testNumber) {

            case 1:
                board[6][6] = Token.CERCLE_ROUGE; //origin and target
                board[6][7] = Token.CERCLE_ROUGE;
                board[6][8] = Token.CERCLE_BLEU;

                board[7][6] = Token.CERCLE_ROUGE;
                board[7][7] = Token.CERCLE_BLEU;
                board[7][8] = Token.CERCLE_BLEU;

                board[8][6] = Token.CERCLE_ROUGE;
                board[8][7] = Token.CERCLE_ROUGE;
                board[8][8] = Token.CERCLE_ROUGE;

                board[5][7] = Token.CERCLE_ROUGE;
                board[5][8] = Token.CERCLE_ROUGE;
                board[5][9] = Token.CERCLE_ROUGE;
                board[6][9] = Token.CERCLE_ROUGE;
                board[7][9] = Token.CERCLE_ROUGE;
                return new int[] {6,6};

            case 2:
                //line 3
                board[3][6] = Token.CERCLE_ROUGE;
                //line 4
                board[4][4] = Token.CERCLE_BLEU; //origin
                board[4][5] = Token.CERCLE_BLEU;
                board[4][6] = Token.CERCLE_BLEU;
                board[4][8] = Token.CERCLE_BLEU;
                //line5
                board[5][3] = Token.CERCLE_BLEU;
                board[5][5] = Token.CERCLE_ROUGE;
                board[5][7] = Token.CERCLE_BLEU;
                board[5][8] = Token.CERCLE_ROUGE;
                board[5][9] = Token.CERCLE_BLEU;
                //line 6
                board[6][2] = Token.CERCLE_BLEU;
                board[6][3] = Token.CERCLE_ROUGE;
                board[6][4] = Token.CERCLE_ROUGE;
                board[6][5] = Token.CERCLE_ROUGE;
                board[6][6] = Token.CERCLE_ROUGE;
                board[6][7] = Token.CERCLE_ROUGE;
                board[6][8] = Token.CERCLE_ROUGE;
                board[6][9] = Token.CERCLE_BLEU;
                //line 7
                board[7][3] = Token.CERCLE_BLEU;
                board[7][4] = Token.CERCLE_BLEU;
                board[7][5] = Token.CERCLE_BLEU;
                board[7][6] = Token.CERCLE_BLEU;
                board[7][7] = Token.CERCLE_ROUGE;
                board[7][8] = Token.CERCLE_BLEU;
                //line 8
                board[8][3] = Token.CERCLE_ROUGE;
                board[8][7] = Token.CERCLE_BLEU;
                board[8][8] = Token.CERCLE_ROUGE;
                board[8][9] = Token.CERCLE_BLEU;
                //line 9
                board[9][7] = Token.CERCLE_ROUGE;
                board[9][8] = Token.CERCLE_BLEU;
                board[9][9] = Token.CERCLE_ROUGE;
                //line 10
                board[10][8] = Token.CERCLE_ROUGE;
                board[10][9] = Token.CERCLE_ROUGE;
                return new int[] {4,4};

            case 0: default:
                    board[6][6] = Token.CERCLE_ROUGE;
                    board[6][7] = Token.CERCLE_ROUGE; //origin and target
                    board[6][8] = Token.CERCLE_BLEU;

                    board[7][6] = Token.CERCLE_ROUGE;
                    board[7][7] = Token.CERCLE_BLEU;
                    board[7][8] = Token.CERCLE_ROUGE;

                    board[8][6] = Token.CERCLE_ROUGE;
                    board[8][7] = Token.CERCLE_ROUGE;
                    board[8][8] = Token.CERCLE_ROUGE;

                    board[5][7] = Token.CERCLE_ROUGE;
                    board[5][8] = Token.CERCLE_ROUGE;
                    board[5][9] = Token.CERCLE_ROUGE;
                    board[6][9] = Token.CERCLE_ROUGE;
                    board[7][9] = Token.CERCLE_ROUGE;
                    return new int[] {6,7};
        }
    }
}

class CellsList extends ArrayList<int[]>{

    @Override  //override to check by the value of int[]
    public boolean contains(Object o) {

        for (int[] a : this) {
            if(Arrays.equals(a, (int[]) o)) {
                return true;
            }
        }

        return false;
    }
}