leetcode_search-in-a-binary-search-tree.cpp

/**
 * Problem : https://leetcode.com/problems/search-in-a-binary-search-tree/
 * 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) {
        while(root!=NULL){
            if(root->val < val){
                root=root->right;
            } else if(root->val > val){
                root=root->left;
            } else{
                return root;
            }
        }
        return NULL;
    }
};