题解 | #二叉搜索树的最近公共祖先#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 *	TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 * };
 */
#include <vector>
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param root TreeNode类 
     * @param p int整型 
     * @param q int整型 
     * @return int整型
     */

    void CollectAllFatherNodes(TreeNode* root,int target,vector<int> &allFathers)
    {
        while(true)
        {
            allFathers.push_back(root->val);
            if(root->val < target)
            {
                root = root->right;
            }
            else if(root->val > target) root = root->left;
            else
            {
                allFathers.push_back(root->val);
                return;
            }
        }
    }
    int lowestCommonAncestor(TreeNode* root, int p, int q) {
        // write code here
        vector<int> pCon;
        vector<int> qCon;
        CollectAllFatherNodes(root,p,pCon);
        CollectAllFatherNodes(root,q,qCon);
        int ans = 0;
        for(int i = 0;i<pCon.size() && i<qCon.size() ;i++)
        {
            if(pCon[i] == qCon[i]) ans = pCon[i];
            else break;
        }
        return ans;
    }
};