CODEWITHSUNDEEP
javascripthtmlalgorithmrecursioncrash
416E64726577
416E64726577

Reputation: 2214

Recursive program crashes computer

I am writing a labyrinth generator, and I am using a Dijkstra Algorithm to see how many parts my labyrinth is divided into.

What I do is I find a cell that does not have a "mark", and run the function "wave".

Function wave(row,column,marknumber):

1) I give this cell a mark. 2) Then, for every nearby cell that is not separated by a wall, I run the function "wave".

This algorithm should tell me how many parts my labyrinth is divided into, but instead my computer screen turns white, starts flashing, and then the computer turns off.

Here is my HTML:

<!DOCTYPE html>
<html>
    <head>
        <script src="/mazeGenerator.js"></script>
    </head>
    <body>
        <canvas id="field" width="300" height="300"></canvas>
        <script>
            var mark = 1;
            init();
            generateBase();
            var arsenalNum = window.prompt("How many arsenals?");
            for (var i=0;i<arsenalNum;i++) {
                arsenal();    
            }
            var prizeNum = window.prompt("How many prizes?");
            for (var i=0;i<prizeNum;i++) {
                prize(i+1);    
            }
            draw();
            for (var r=0; r<DIM; r++) {
                for (var c=0; c<DIM; c++) {
                    if (maze[r][c].mark === 0) {
                        draw();
                        //alert(" ");
                        wave(r,c,mark);
                        mark++;
                    }
                }
            }
            draw();
            alert("There are " + numberOfMarks() + " marks in this labyrinth.");
        </script>
    </body>
</html>

And here is my Javascript:

var DIM = window.prompt("Please choose a dimension.");
var maze = new Array (DIM);

// init();
// generate();
// draw();

function init() {
    for (var i=0;i<DIM;i++) {
        maze[i] = new Array (DIM);
        for (var j=0;j<DIM;j++) {
            maze[i][j] = {
                "walls":[0,0,0,0],
                "mark":0,
                "hole":-1,
                "arsenal":0,
                "prize":0,
                "blocks_arsenal_entrance":0
            };
        }
    }    
}

function generateBase() {
    for (var r=0;r<DIM;r++) {
        for (var c=0;c<DIM;c++) {
            var ind = Math.floor(Math.random()*4);
            addWall(r,c,ind);
            if (r === 0) {
                maze[r][c].walls[0] = 1;
            }
            if (c === (DIM-1)) {
                maze[r][c].walls[1] = 1;
            }
            if (r === (DIM-1)) {
                maze[r][c].walls[2] = 1;
            }
            if (c === 0) {
                maze[r][c].walls[3] = 1;
            }
        }
    }
}

function draw() {
    var canvas=document.getElementById("field");
    var ctx=canvas.getContext("2d");
    for (var r=0;r<DIM;r++) {
        for (var c=0;c<DIM;c++) {
            drawCell(r,c,ctx);
        }
    }
}

function drawCell(r,c,ctx) {
    var left = c*10;
    var top = r*10;
    var w = maze[r][c].walls;
    if (w[0] === 1) {
        ctx.moveTo(left,top);
        ctx.lineTo((left+10),top);
        ctx.stroke();
    }
    if (w[1] === 1) {
        ctx.moveTo((left+10),top);
        ctx.lineTo((left+10),(top+10));
        ctx.stroke();
    }
    if (w[2] === 1) {
        ctx.moveTo(left,(top+10));
        ctx.lineTo((left+10),(top+10));
        ctx.stroke();
    }
    if (w[3] === 1) {
        ctx.moveTo(left,top);
        ctx.lineTo((left),(top+10));
        ctx.stroke();
    }
    if (maze[r][c].arsenal == 1) {
        ctx.fillStyle = "#FF0000";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].prize !== 0) {
        ctx.fillStyle = "#00FF00";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 1) {
        ctx.fillStyle = "#FF00FF";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 2) {
        ctx.fillStyle = "#FFFF00";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 3) {
        ctx.fillStyle = "#00FFFF";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 4) {
        ctx.fillStyle = "#0080FF";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 5) {
        ctx.fillStyle = "#FF0080";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 6) {
        ctx.fillStyle = "#FFFFFF";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 7) {
        ctx.fillStyle = "#000000";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 8) {
        ctx.fillStyle = "#80FF80";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 9) {
        ctx.fillStyle = "#8080FF";
        ctx.fillRect(left,top,10,10);
    }
    if (maze[r][c].mark === 10) {
        ctx.fillStyle = "#FF8080";
        ctx.fillRect(left,top,10,10);
    }
}

function up(r,c) {
    if (r === 0) {
        return null;
    } else {
        return maze[r-1][c];
    }
}

function down(r,c) {
    if (r == (DIM - 1)) {
        return null;
    } else {
        return maze[r+1][c];
    }
}

function left(r,c) {
    if (c === 0) {
        return null;
    } else {
        return maze[r][c-1];
    }
}

function right(r,c) {
    if (c == (DIM - 1)) {
        return null;
    } else {
        return maze[r][c+1];
    }
}

function neighbor(r,c,dir) {
    if (dir === 0) {
        return up(r,c);
    }
    if (dir === 1) {
        return right(r,c);
    }
    if (dir === 2) {
        return down(r,c);
    }
    if (dir === 3) {
        return left(r,c);
    }
}

function opposite(dir) {
    if (dir === 0) {
        return 2;
    }
    if (dir === 1) {
        return 3;
    }
    if (dir === 2) {
        return 0;
    }
    if (dir === 3) {
        return 1;
    }
}

function arsenal() {
    var done = false;
    while (!done) {
        var r = Math.floor(Math.random()*DIM);
        var c = Math.floor(Math.random()*DIM);
        if (maze[r][c].prize !== 0) {
            continue;
        }

        if (maze[r][c].arsenal !== 0) {
            continue;
        }

        if (maze[r][c].blocks_arsenal_entrance !== 0) {
            continue;
        }

        var entrance = Math.floor(Math.random()*4);

        if ((r === 0) && (entrance === 0)) {
            entrance = opposite(entrance);
        }

        if ((c === (DIM - 1)) && (entrance === 1)) {
            entrance = opposite(entrance);
        }

        if ((r === (DIM - 1)) && (entrance === 2)) {
            entrance = opposite(entrance);
        }

        if ((c === 0) && (entrance === 3)) {
            entrance = opposite(entrance);
        }

        for (var d=0;d<4;d++) {
            removeWall(r,c,d);
        }

        for (d=0;d<4;d++) {
            if (d !== entrance) {
                addWall(r,c,d);
            }
        }
        neighbor(r,c,entrance).blocks_arsenal_entrance = 1;
        maze[r][c].arsenal = 1;
        done = true;

    }
}

function prize(n) {
    var done = false;
    while (!done) {
        var r = Math.floor(Math.random()*DIM);
        var c = Math.floor(Math.random()*DIM);

        if (maze[r][c].prize !== 0) {
            continue;
        }

        if (maze[r][c].arsenal !== 0) {
            continue;
        }

        if (maze[r][c].blocks_arsenal_entrance !== 0) {
            continue;
        }

        for (var d=0;d<4;d++) {
            addWall(r,c,d);
        }

        maze[r][c].prize = n;
        done = true;

    }
}

function addWall(r,c,ind) {
    maze[r][c].walls[ind] = 1;
    if (neighbor(r,c,ind) !== null) {
        neighbor(r,c,ind).walls[opposite(ind)] = 1;
    }
}

function removeWall(r,c,dir) {
    maze[r][c].walls[dir] = 0;
    var neighborCell = neighbor(r,c,dir);
    if (neighborCell !== null) {
        neighborCell.walls[opposite(dir)] = 0;
    }
}

function wave(r,c,mark) {
    //alert("Wave Started with " + r + ", " + c + ".");
    if (maze[r][c].mark === 0) {//Make sure the cell doesn't have a mark
        // alert(r + ", " + c + " does not have a mark.");
        maze[r][c].mark = mark;
        // alert("maze["+r+"]["+c+"].mark is now equal to " + maze[r][c].mark);
        if ((maze[r][c].walls[0] === 0) && (up(r,c).mark === 0)) {
            wave((r-1),c);
        }
        if ((maze[r][c].walls[1] === 0) && (right(r,c).mark === 0)) {
            wave(r,(c+1));
        }
        if ((maze[r][c].walls[2] === 0) && (down(r,c).mark === 0)) {
            wave((r+1),c);
        }
        if ((maze[r][c].walls[3] === 0) && (left(r,c).mark === 0)) {
            wave(r,(c-1));
        }
    } else {

    }
}

function numberOfMarks() {
    var maxMark = 0;
    for (var r=0;r<DIM;r++) {
        for (var c=0;c<DIM;c++) {
            if ((maze[r][c].mark) > maxMark) {
                maxMark = maze[r][c].mark;
            }
        }
    }
    return maxMark;
}

function numberOfPrizes() {
    var maxPrize = 0;
    for (var r=0;r<DIM;r++) {
        for (var c=0;c<DIM;c++) {
            if ((maze[r][c].prize) > maxPrize) {
                maxPrize = maze[r][c].prize;
            }
        }
    }
    return maxPrize;
}

function findMarkBorder() {
    for (var r=0;r<DIM;r++) {
        for (var c=0;c<DIM;c++) {
            if (((maze[r][c].mark) !== up(r,c).mark) && (up(r,c).mark !== null)) {
                document.write("<br> The cell above cell "+r+", "+c+" has a different mark.");
            }
            if (((maze[r][c].mark) !== right(r,c).mark) && (right(r,c).mark !== null)) {
                document.write("<br> The cell to the right of cell "+r+", "+c+" has a different mark.");
            }
            if (((maze[r][c].mark) !== down(r,c).mark) && (down(r,c).mark !== null)) {
                document.write("<br> The cell below cell "+r+", "+c+" has a different mark.");
            }
            if (((maze[r][c].mark) !== left(r,c).mark) && (left(r,c).mark !== null)) {
                document.write("<br> The cell to the left of cell "+r+", "+c+" has a different mark.");
            }
        }
    }   
}

Please tell me what I am doing wrong! Thanks in advance!

Upvotes: 1

Views: 340

Answers (1)

user3238231
user3238231

Reputation: 86

This program is not working, because in the function wave, you are not passing enough arguments -- you are not passing the "mark".

For example,

    if ((maze[r][c].walls[3] === 0) && (left(r,c).mark === 0)) {
        wave(r,(c-1));
    }

should be

    if ((maze[r][c].walls[3] === 0) && (left(r,c).mark === 0)) {
        wave(r,(c-1),mark);
    }

Upvotes: 1

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