how to find an node exist or not in binary tree in java?

Question

I tried this, but I am getting compile time error. What I am missing ? I also have to return false if the element not found

public boolean search(Node root, Node node){
        if(root==node){
            return true;
        }
        if(root.getLeft()!=null){
            search(root.getLeft(), node);
        }

        if(root.getRight()!=null){
            search(root.getRight(), node);
        }
    }

My answer covered the compile error but you also have an algorithm error. I deleted the answer. — Arnaud Denoyelle
– Arnaud Denoyelle, Commented Feb 10, 2015 at 9:38

Arnaud Denoyelle · Accepted Answer · 2015-02-10 09:41:09Z

4

You have a compile error because you don't always return something :

    if(root.getLeft()!=null){
        search(root.getLeft(), node);
    }

    if(root.getRight()!=null){
        search(root.getRight(), node);
    }

This would fix the compile error but not the algorithm :

    if(root.getLeft()!=null){
       return search(root.getLeft(), node);
    }

    if(root.getRight()!=null){
        return search(root.getRight(), node);
    }

This should fix the algorithm :

    if(root.getLeft()!=null && search(root.getLeft(), node)) {
      return true;
    }

    if(root.getRight()!=null && search(root.getRight(), node)){
       return true;
    }
    return false;

edited Feb 10, 2015 at 9:41

answered Feb 10, 2015 at 9:33

Arnaud Denoyelle

31.5k18 gold badges106 silver badges161 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

testzuser Over a year ago

what if the element not found ? i have to return false

flynn · Accepted Answer · 2015-02-10 09:48:00Z

1

public boolean search(Node root, Node node){
    if(root == node){
        return true;
    }
    boolean found = false;

    if(root.getLeft() != null ){
        found = search(root.getLeft(), node);
    }

    if(!found && root.getRight() != null )
    {
        found = search(root.getRight(), node);
    }

    return found;
}

answered Feb 10, 2015 at 9:48

flynn

331 silver badge6 bronze badges

Collectives™ on Stack Overflow

how to find an node exist or not in binary tree in java?

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related