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 grid = [];

var openSet = [];

var closedSet = [];

var path = [];

var rows = 50;

var cols = 50;

var start;

var end;

var w,h; 

var current;

​

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(c){

    fill(c);

    if(this.wall){

      fill(0);

    }

    noStroke(0);

    rect(this.i * w,this.j * h,w,h)

  }

  this.addNeighbors = function(grid){

    if(i<cols - 1){

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

    }

    if(i>0){

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

    }

    if(j < rows-1){

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

    }

    if(j > 0){

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

    }

  }

}

​

function setup() {

  createCanvas(400, 400);

  console.log('A*');

  w = width/cols;

  h = height/rows;

  for(let i = 0; i < cols; i++){

    grid[i] = [];

    for(let j = 0; j < rows; j++){

      grid[i][j] = new Spot(i,j);

    }

  }

  for(let i = 0; i < cols; i++){

    for(let 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() {

  aStar();

}

​

function aStar(){

  for(var i = 0; i <4; i++){

  if(openSet.length > 0){

    var winner = 0;

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

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

        winner = i;

      }

    }

    current = openSet[winner];

    if(current == end){

      noLoop();

      console.log("done");

    }

    removeFromArray(openSet,current);

    closedSet.push(current);

    var neighbors = current.neighbors;

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

      var neighbor = neighbors[i];

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

        var tempG = current.g + 1;

        if(openSet.includes(neighbor)){

          if(tempG < neighbor.g){

            neighbor.g = tempG;

          }

        }else{

          neighbor.g = tempG;

          openSet.push(neighbor);

        }

        neighbor.h = heuristic(neighbor,end);

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

        neighbor.previous = current;

      }

    }

  }else{

    console.log('No Solution')

    noLoop();

    //no solution

  }

  }

  //background(0);

  for(let i = 0; i < cols; i++){

    for(let j = 0; j < cols; j++){

      grid[i][j].show(color(255));

    }

  }

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

    var d = heuristic(closedSet[i],end);

    closedSet[i].show(color(map(d,cols+rows,0,100,255),map(d,cols+rows,0,0,255),0));

  }

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

    openSet[i].show(color(0,200,0));

  }

  path = [];

  var temp = current;

  path.push(temp);

  while(temp.previous){

    path.push(temp.previous);

    temp = temp.previous;

  }

​

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

    path[i].show(color(0,0,255));

  }

}