for (var i = arr.length - 1; i >= 0; i--) {

    if (arr[i] == elt) {

      arr.splice(i, 1);

    }

  }

}

​

function heuristic(a, b) {

  // var d = dist(a.i, a.j, b.i, b.j);

  var d = abs(a.i - b.i) + abs(a.j - b.j);

  return d;

}

​

var cols = 50;

var rows = 50;

var grid = new Array(cols);

​

var openSet = [];

var closedSet = [];

var start;

var end;

var w, h;

var path = [];

var nosolution = false;

​

function Spot(i, j) {

  this.i = i;

  this.j = j;

  this.f = 0;

  this.g = 0;

  this.h = 0;

  this.neighbors = [];

  this.previous = undefined;

  this.wall = false;

​

  if (random(1) < 0.3) {

    this.wall = true;

  }

​

  this.show = function(col) {

    if (this.wall) {

      fill(255);

      noStroke();

      ellipse(this.i * w + w / 2, this.j * h + h / 2, w / 2, h / 2);

    }

    // rect(this.i * w, this.j * h, w - 1, h - 1);

  }

​

  this.addNeighbors = function(grid) {

    var i = this.i;

    var j = this.j;

    if (i < cols - 1) {

      this.neighbors.push(grid[i + 1][j]);

    }

    if (i > 0) {

      this.neighbors.push(grid[i - 1][j]);

    }

    if (j < rows - 1) {

      this.neighbors.push(grid[i][j + 1]);

    }

    if (j > 0) {

      this.neighbors.push(grid[i][j - 1]);

    }

    if (i > 0 && j > 0) {

      this.neighbors.push(grid[i - 1][j - 1]);

    }

    if (i < cols - 1 && j > 0) {

      this.neighbors.push(grid[i + 1][j - 1]);

    }

    if (i > 0 && j < rows - 1) {

      this.neighbors.push(grid[i - 1][j + 1]);

    }

    if (i < cols - 1 && j < rows - 1) {

      this.neighbors.push(grid[i + 1][j + 1]);

    }

  }

}

​

function setup() {

  createCanvas(800, 800);

​

  w = width / cols;

  h = height / rows;

​

  // Making a 2D Array

  for (var i = 0; i < cols; i++) {

    grid[i] = new Array(rows);

  }

​

  for (var i = 0; i < cols; i++) {

    for (var j = 0; j < rows; j++) {

      grid[i][j] = new Spot(i, j);

    }

  }

​

  for (var i = 0; i < cols; i++) {

    for (var j = 0; j < rows; j++) {

      grid[i][j].addNeighbors(grid);

    }

  }

​

  start = grid[0][0];

  end = grid[cols - 1][rows - 1];

  start.wall = false;

  end.wall = false;

​

  openSet.push(start);

}

​

function draw() {

  background(0);

  frameRate(10);

​

  if (openSet.length > 0) {

​

    var winner = 0;

    for (var i = 0; i < openSet.length; i++) {

      if (openSet[i].f < openSet[winner].f) {

        winner = i;

      }

    }

    var current = openSet[winner];

​

    if (current === end) {

      noLoop();

      console.log("Done.");

    }

​

    removeFromArray(openSet, current);

    // openSet.remove(current);

    closedSet.push(current);

​

    var neighbors = current.neighbors;

    for (var i = 0; i < neighbors.length; i++) {

      var neighbor = neighbors[i];

      if (!closedSet.includes(neighbor) && !neighbor.wall) {

        var tempG = current.g + 1;

​

        var newPath = false;

        if (openSet.includes(neighbor)) {

          if (tempG < neighbor.g) {

            neighbor.g = tempG;

            newPath = true;

          }

        } else {

          neighbor.g = tempG;

          openSet.push(neighbor);

          newPath = true;

        }

        if (newPath) {

          neighbor.h = heuristic(neighbor, end);

          neighbor.f = neighbor.g + neighbor.h;

          neighbor.previous = current;

        }

      }

    }

​

    // we can keep going

  } else {

    console.log("No solution.");

    nosolution = true;

    noLoop();

  }

​

  for (var i = 0; i < cols; i++) {

    for (var j = 0; j < rows; j++) {

      grid[i][j].show(color(255));

    }

  }

​

//   for (var i = 0; i < closedSet.length; i++) {

//     closedSet[i].show(color(255, 0, 0));

//   }

​

//   for (var i = 0; i < openSet.length; i++) {

//     openSet[i].show(color(0, 255, 0));

//   }

​

  // Find the path

  if (!nosolution) {

    path = [];

    var temp = current;

    path.push(temp);

    while (temp.previous) {

      path.push(temp.previous);

      temp = temp.previous;

    }

  }

​

  // for (var i = 0; i < path.length; i++) {

  //   path[i].show(color(0, 0, 255));

  // }

  noFill();

  stroke(255, 255, 0);

  strokeWeight(5);

  beginShape();

  for (var i = 0; i < path.length; i++) {

    vertex(path[i].i * w + w / 2, path[i].j * h + h / 2);

  }

  endShape();

  fill(255, 255, 0);

  ellipse(path[0].i * w + w / 2, path[0].j * h + h / 2, 10, 10);

}