JAVA - 打印节点+二叉搜索树的深度

Question

Im trying to print all values and depth for each node of my binary search tree. Im having trouble coming up with a way to count the depth recursively. So far I have a method for only printing each value of the tree. I would appreciate some guidance because I feel like Im making it harder than it should be.

public void printTree( )
    {
        if( isEmpty( ) )
            System.out.println( "Empty tree" );
        else
            printTree( root );
    }

Answer 1

I do not see any code for printing the tree, but other than that the print function is not complete either. To print the whole tree you can rely on any tree traversal algorithms. Here is sample code to return depth and print the tree in pre-order.

public static void printTree(Node r) {
    if( r==null )
        return;
    System.out.println(r.value);
    printTree(r.left);
    printTree(r.right);
}

public static int findDepth (Node r) {
    if(r==null)
      return 0;
    return (max(findDepth(r.left),findDepth(r.right))+1);
}

This is based assuming a Node class is defined as below.

class Node {
int value;
Node left;
Node right;

Node(int value) {
    this.value = value;
    right = null;
    left = null;
}

}

you may need to build tree for testing in a separate function or inside main.