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) {}
 * };
 */
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
     */
    int lowestCommonAncestor(TreeNode* root, int p, int q) {
        auto solve = [&p, &q](auto&& solve, TreeNode* n) -> int {
            if(p > n->val and q > n->val) {
                return solve(solve, n->right);
            } else if(p < n->val and q < n->val) {
                return solve(solve, n->left);
            } else {
                return n->val;
            }
        };
        return solve(solve, root);
    }
};