题解 | #二叉搜索树的第k个结点#
二叉搜索树的第k个结点
http://www.nowcoder.com/practice/ef068f602dde4d28aab2b210e859150a
时间空间都 满足，缺陷是使用了全局变量。恳请各位大佬指点。
/*
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
TreeNode(int x) :
val(x), left(NULL), right(NULL) {
}
};
*/
class Solution {
public:
TreeNode* res;
int n = 0;
TreeNode* KthNode(TreeNode* pRoot, int k) {
SearchNode(pRoot, k);
return res;
}
void SearchNode(TreeNode* pRoot, int k){
if(pRoot == NULL){
return;
}
KthNode(pRoot->left, k);
n++;
if(n == k){
res = pRoot;
}
KthNode(pRoot->right, k);
}
};
