Search in a Binary Search Tree

Category

Binary Search Tree

Checkbox

Difficulty

Easy

Index

Key Ideas

The key idea to solve the problem in LeetCode-75 is to perform a binary search on a binary search tree, comparing the target value with the values at each node to determine the next move in the search.

Problem Number

700

Problem Summary

Problem Summary: The problem number 700 in the LeetCode-75 curated list is about searching for a value in a binary search tree (BST). Given a BST and a target value, the task is to find the node in the BST that has the same value as the target. If such a node exists, return its reference; otherwise, return null. Key Pitfalls: - One key pitfall is not utilizing the property of a BST, where the values in the left subtree are smaller than the current node and the values in the right subtree are greater. - Another pitfall is not handling the case when the target value is not present in the BST, which requires properly traversing the tree and checking for null references. - It is important to handle edge cases, such as an empty BST or when the target value is null or invalid.

Solution Summary

The best solution to solve the problem in LeetCode-75 curated list is to perform a binary search on the given binary search tree. Start at the root node and compare the target value with the current node's value. If the target is smaller, move to the left child node; if it's larger, move to the right child node. Repeat this process until the target value is found or until reaching a null node. If the target value is found, return the corresponding node; otherwise, return null to indicate that the target value is not present in the binary search tree. This solution has a time complexity of O(log n) in the average case and O(n) in the worst case, where n is the number of nodes in the binary search tree.