https://codecombat.com/play/level/gridmancer (incompletion)

gridmancer.js

// Fill the empty space with the minimum number of rectangles.
// (Rectangles should not overlap each other or walls.)
// The grid size is 1 meter, but the smallest wall/floor tile is 4 meters.
// Check the blue guide button at the top for more info.
// Make sure to sign up on the home page to save your code.

var grid = this.getNavGrid().grid;
var tileSize = 4;
var width = tileSize;
for(var y = 0; y + tileSize < grid.length; y += tileSize) {
    for(var x = 0; x + tileSize < grid[0].length; x += width) {
        var occupied = grid[y][x].length > 0;
        width = tileSize;
        if(!occupied) {
            while(grid[y][x+width].length<=0)
                width+=tileSize;
            this.addRect(x + width / 2, y + tileSize/ 2, width,tileSize);
            this.wait();  // Hover over the timeline to help debug!
        }
    }
}

var flag = true;
while(flag){
  flag = false;
  for(var i=0;i<this.spawnedRectangles.length;i++){
      var rect1 = this.spawnedRectangles[i];
      for(var j=i+1;j<this.spawnedRectangles.length;j++){
          var rect2 = this.spawnedRectangles[j];
          if(rect1.pos.x==rect2.pos.x && (((rect2.pos.y-rect2.height/2)-(rect1.pos.y+rect1.height/2)<4&&(rect2.pos.y-rect2.height/2)-(rect1.pos.y+rect1.height/2)>-4)||((rect1.pos.y-rect1.height/2)-(rect2.pos.y+rect2.height/2)<4&&(rect1.pos.y-rect1.height/2)-(rect2.pos.y+rect2.height/2)>-4)) && rect1.width==rect2.width){
              width = rect1.width;
              height = rect1.height+rect2.height;
              x = rect1.pos.x;
              y = rect1.pos.y * rect1.height/height + rect2.pos.y * rect2.height/height;
              this.removeRectAt(rect1.pos.x,rect1.pos.y);
              this.removeRectAt(rect2.pos.x,rect2.pos.y);
              this.addRect(x,y,width,height);
              flag = true;
              this.wait();  // Hover over the timeline to help debug!
              break;
          }
      }
  }
}

num = 5;  //1回じゃ全更新できない
while(num>0){
  for(i=0;i<this.spawnedRectangles.length;i++){
      x = this.spawnedRectangles[i].pos.x;
      y = this.spawnedRectangles[i].pos.y;
      width = this.spawnedRectangles[i].width;
      height = this.spawnedRectangles[i].height;
  
      this.removeRectAt(x,y);
      this.addRect(x,y,width,height);
      this.wait();  // Hover over the timeline to help debug!
}
num--;
}