Inorder Predecessor and Successor in BST

Problem Statement

Pattern:

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Solution

Node inorderPredecessor(Node node, int key) {
	Node pre = null;
	
	while(node != null) {
		if(key <= node.data) node = node.left;
		else {
			pre = node;
			node = node.right;
	}   }
	
	return pre;
}
 
Node inorderSuccessor(Node node, int key) {
	Node succ = null;
	
	while(node != null) {
		if(key >= node.data) node = node.right;
		else {
			succ = node;
			node = node.left;
	}   }
	
	return succ;
}

Notes