Question

所以我运行了我的Astar程序并运行了4次，但是它有时会出现两个不同的数组错误。

我认为这是边界检查的问题，但我认为我的边界检查正确。任何人都可以帮助指出问题所在吗？

public class myastar extends astar
{
    public myastar(int r, int c) { super(r,c); }


    static final int NEW =0;
    static final int INTERIOR =1;
    static final int FRONTIER =2;
    int[][] Status = new int[ROWS][COLS]; //initialize a new matrix of all 0s--keep track of status of node

    public coord search(int sy, int sx, int ty, int tx)
    {
        coord start = new coord (sy, sx);
        start.dist = 0;
        start.cost=0;
        coord current = null;

        //create frontier heap
        pheap<coord> Frontier = new pheap<coord>(new coord[1000]);

        //Insert start into frontier
        Frontier.insert(start);

        //Status
        Status [sy][sx] = FRONTIER;

        //Boolean value of when to stop while
        boolean stop = false;

        //cost
        int []cost = {1, 0, 0, 5};

        while(!stop && Frontier.size() != 0)
        {            
            current = Frontier.deletetop();
            Status[current.y][current.x] = INTERIOR;

            int i = current.y;
            int j = current.x;

            coord neighborn = new coord(i-1, j); //NORTH
            coord neighborw = new coord(i, j-1); //WEST
            coord neighbore = new coord(i, j+1); //EAST
            coord neighbors = new coord(i+1, j); //SOUTH

            if (i>0 && i-1>0){
            //North
            neighborn.dist = current.dist + 1;
            neighborn.cost = neighborn.dist + cost[M[i-1][j]] + ddist(i-1, j, ty, tx);
            }

            if (j>0 && j-1>0){

            //West
            neighborw.dist = current.dist + 1;
            neighborw.cost = neighborw.dist + cost[M[i][j-1]] + ddist(i, j-1, ty, tx);
            }

            if (j<COLS && j+1<COLS){
            //East
            neighbore.dist = current.dist + 1;
            neighbore.cost = neighbore.dist+ cost[M[i][j+1]] + ddist(i, j+1, ty, tx);
            }

            if (i<ROWS && i+1<ROWS ){
            //South
            neighbors.dist = current.dist + 1;
            neighbors.cost = neighbors.dist+ cost[M[i+1][j]] + ddist(i+1, j, ty, tx);
            }

            boolean a = true;
            if(i<=0){a=false;}
            boolean b = false;
            boolean c = false;
            boolean d = false;
            if(neighborw.compareTo(neighborn) > 0){b=true;a=false;}
            if(j<=0){b=false;}
            if(neighbore.compareTo(neighborw) > 0){c=true;b=false;}
            if(i>=COLS){c=false;}
            if(neighbors.compareTo(neighbore) > 0){d=true;c=false;}
            if(j>=ROWS){d=false;}


            if(Status[i-1][j] != FRONTIER && Status[i-1][j] != INTERIOR && i>0 && a)// M[i-1][j] == OPEN && i>0 && a)
            {
                Frontier.insert(neighborn); //NORTH
                neighborn.prev = current;
                Status[i-1][j] = FRONTIER;
                System.out.println("north");
            }
            if(Status[i][j-1] != FRONTIER && Status[i][j-1] != INTERIOR && j>0 && b)// M[i][j-1] == OPEN && j>0 && b)
            {
                Frontier.insert(neighborw); //WEST
                neighborw.prev = current;
                Status[i][j-1] = FRONTIER;
                System.out.println("west");
            }
            if(Status[i][j+1] != FRONTIER && Status[i][j+1] != INTERIOR && j<COLS && c)// M[i][j+1] == OPEN && j<COLS && c)
            {
                Frontier.insert(neighbore); //EAST
                neighbore.prev = current;
                Status[i][j+1] = FRONTIER;
                System.out.println("east");
            }
            if(Status[i+1][j] != FRONTIER && Status[i+1][j] != INTERIOR && i<ROWS && d)// M[i+1][j] == OPEN && i<ROWS && d)
            {
                Frontier.insert(neighbors); //SOUTH
                neighbors.prev = current;
                Status[i+1][j] = FRONTIER;
                System.out.println("south");
            }
            if(i==ty && j == tx){stop = true;}
        }
        return current;
    }
}

Answer 1

if(Status[i-1][j] != FRONTIER && Status[i-1][j] != INTERIOR && i>0 && a)

您应该将i > 0放在i - 1之前，让短路阻止i - 1为-1。

此外，i>0 && i-1>0只是j > 1。

Astar边界检查

1 个答案: