题目
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.
答案
class Solution {
// Iterate the tree, if p is found, then next treenode to be visited is its successor
public TreeNode inorderSuccessor(TreeNode root, TreeNode p) {
if(root == null) return null;
TreeNode ans = null;
while(root != null) {
if(root.val > p.val) {
// root could be p's successor
ans = root;
root = root.left;
}
else {
root = root.right;
}
}
return ans;
}
}
