235. Lowest Common Ancestor of a Binary Search Tree

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.

According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has both v and w as descendants (where we allowa node to be a descendant of itself).”

        _______6______       /              \    ___2__          ___8__   /      \        /      \   0      _4       7       9         /  \         3   5

For example, the lowest common ancestor (LCA) of nodes 2 and 8 is 6. Another example is LCA of nodes 2 and 4 is 2, since a node can be a descendant of itself according to the LCA definition.

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这题做的不是很好。
代码

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    bool findNode(TreeNode* root, TreeNode* p,vector<TreeNode*>& result)    {        if(root == NULL)        {            return  false;        }        if(root ==  p)        {            result.push_back(root);            return  true;        }        bool temp=false;                if(!temp)        {   result.push_back(root);            temp=findNode(root->left,p,result)||findNode(root->right,p,result);            if(!temp)            result.pop_back();        }        return temp;    }    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {        vector<TreeNode*> p1;        vector<TreeNode*> p2;        findNode(root,p,p1);        findNode(root,q,p2);        int len1=p1.size();        int len2=p2.size();        int t   =min(len1,len2);        while(--t>=0)        {            if(p1[t]==p2[t])            return p1[t];        }                return p1[0];    }};