K-large node binary search tree: face questions fifty-four

 

Method: binary tree search feature is less than the left node tree, the tree node is less than the right, so the method using the preorder ordered sequence can be obtained

BinaryTreeNode KthNode（BinaryTreeNode pNode ,int k）{
            if( pNode ==null||k==0)
            return null;
           return KthNodeCore(pNode ,k );
    }
BinaryTreeNode  KthNodeCore(BinaryTreeNode pNode ,int k ){
                Target BinaryTreeNode = null ;
                 // traversal recursion starts to a minimum 
                IF (pNode.L =! Null )
                     target = KthNodeCore (pNode.L, K);
                 // K as a condition   
                IF (target == null ) {
                     IF (K ==. 1 )
                        target=pNpde;
                     k--;
                }
                if( target==null && pNode.R==null)
                        target=KthNodeCore(pNode.R ,k );
                return target;
}