Leetcode|BST属性|700. BST搜索

if (val < root->val) {...}
else if (val > root->val) {...}

if (val < root->val) {...}
if (val > root->val) {...}

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    TreeNode* searchBST(TreeNode* root, int val) {
        if (!root) return nullptr;
        if (val < root->val) root = searchBST(root->left, val);
        else if (val > root->val) root = searchBST(root->right, val);
        return root;
    }
};

class Solution {
public:
    TreeNode* searchBST(TreeNode* root, int val) {
        while (root) {
            if (val < root->val) root = root->left;
            else if (val > root->val) root = root->right;
            else break;
        }
        return root;
    }
};