题解 | #二叉搜索树的第k个结点# 减法求解
二叉搜索树的第k个结点
http://www.nowcoder.com/practice/ef068f602dde4d28aab2b210e859150a
public class Solution {
private TreeNode res;
private int idx;
TreeNode KthNode(TreeNode pRoot, int k) {
idx=k;
dfs(pRoot);
return res;
}
private void dfs(TreeNode node){
if(node==null) return;
dfs(node.left);
if(idx==0) return;
if(--idx==0) res = node;
dfs(node.right);
}
}
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