so im getting a stack overflow error:this sketch is attempting too much recursion error. i understand why but i have no idea how to go about fixing it as i need to recursively check a set of values in an arraylist. any help would be greatly appreciated   the issue is cropping up at the end of my blockcheck() function so you know where to look.

Code:

ArrayList blocks = new ArrayList();
ArrayList adjlocs = new ArrayList();
public int tracer = 0;

void setup(){
  size(960,600);
  for(int i = 0; i< 10;i++){
    for(int x = 0; x< 10;x++){
      blocks.add(new Block(width/2+i*25, height/2+x*25, 25, int(random(0,2))));
    }
  }
  println(blocks.size());
}

void draw(){
  background(0);
  for(int i=0;i<blocks.size();i++){
    Block tempblock = (Block) blocks.get(i);
      if(tempblock.activated == false){
        tempblock.display();
      }
      else{
        tempblock.nodisplay();
      }
    }
  }


void mouseClicked(){
  for(int i=0;i<blocks.size();i++){
    Block tempblock = (Block) blocks.get(i);
      if(dist(mouseX, mouseY, tempblock.blockx, tempblock.blocky) <=12.5){
        tempblock.activated = true;
        println(i);
        blockcheck(i);
      }
    }
  }

class Block{
  public float blockx;
  public float blocky;
  private float blocksize;
  public boolean activated;
  public int type;

  Block(float x, float y, float _blocksize, int _type){
    blockx = x;
    blocky = y;
    blocksize = _blocksize;
    activated = false;
    type = _type;
  }

  void nodisplay(){
    
  }

  void display(){
    if(activated == false){
      strokeWeight(1);
      if(this.type == 0){
        stroke(0,80,250);
      }
      else if(this.type == 1){
        stroke(250,45,45);
      }
    }
    else if(activated == true){
      strokeWeight(2);
      if(this.type == 0){
        stroke(0,80,250);
      }
      else if(this.type == 1){
        stroke(250,45,45);
      }
    }
    if(this.type == 0){
      fill(0,80,250,75);
    }
    else if(this.type == 1){
      fill(250,45,45,75);
    }
    rectMode(CENTER);
    rect(blockx, blocky, blocksize,blocksize);

  }
}

void blockcheck(int pos){
  Block tempblock = (Block) blocks.get(pos);

  //top
  if(pos !=0 && pos%10 != 0){
    Block topblock = (Block) blocks.get(pos-1);
    if(topblock.type == tempblock.type){
      topblock.activated = true;
      adjlocs.add(new Checkint(pos-1));
    }
  }

  //right
  if(pos >= 90){
  }
  else{
    Block rightblock = (Block) blocks.get(pos+10);
    if(rightblock.type == tempblock.type){
      rightblock.activated = true;
      adjlocs.add(new Checkint(pos+10));
    }
  }

  //bottom
  if(pos%10 != 9 ){
    Block bottomblock = (Block) blocks.get(pos+1);
    if(bottomblock.type == tempblock.type){
      bottomblock.activated = true;
      adjlocs.add(new Checkint(pos+1));
    }
  }

  //left
  if(pos <= 9){
  }
  else{
    Block leftblock = (Block) blocks.get(pos-10);
    if(leftblock.type == tempblock.type){
      leftblock.activated = true;
      adjlocs.add(new Checkint(pos-10));
    }
  }

  if(adjlocs.size() != 0){
    Checkint tempint = (Checkint) adjlocs.get(0);
    int  newpos = tempint.posvalue;
    //println(adjlocs);
    if(pos == newpos){
      adjlocs.remove(0);
    }

    blockcheck(newpos);
  }
}

class Checkint{
  int posvalue;
  
  Checkint(int temp){
    posvalue = temp;
  }
}
 

nope, didn't help, same problem, slightly different values.

what is the code meant to be doing? it helps to know what we're meant to be debugging...

seed fill?

like Minefield? that's a seed fill or a flood fill.

http://en.wikipedia.org/wiki/Flood_fill

which is probably the second most famous recursive algorithm after exponential numbers (but like all recursive stuff is fiddly to implement).

might be easier to use an iterative method rather than a recursive one:

put initial position in a list.

while there are things in the list {
 remove first thing from list
 make it 'disappear'
 add similar coloured neighbours to end of list
}

awesome that should hopefully be enough for me to figure out what it going on, thanks for all your help