285 Inorder Successor in BST
Problem:
Given a binary search tree and a node in it, find the in-order successor of that node in the BST.
Note: If the given node has no in-order successor in the tree, return null.
Solutions:
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public TreeNode inorderSuccessor(TreeNode root, TreeNode p) {
if (p.right != null) {
TreeNode node = p.right;
while (node.left != null) {
node = node.left;
}
return node;
}
TreeNode node = root;
TreeNode min = null;
while (node != p && node != null) {
if (node.val < p.val) {
node = node.right;
}
else {
min = node;
node = node.left;
}
}
return min;
}
}