Leetcode：面试题68

Leetcode：面试题68 - II. 二叉树的最近公共祖先

Leetcode：面试题68 - II. 二叉树的最近公共祖先

Talk is cheap . Show me the code .

/**
 * 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:
    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
        if(root==NULL||p==root||q==root) return root;
        TreeNode *left,*right;
        left=lowestCommonAncestor(root->left,p,q);
        right=lowestCommonAncestor(root->right,p,q);
        if(left==NULL) return right;
        if(right==NULL) return left;
        return root;
    }
};