SDE-3

Given the head of a linked list, remove the nth node from the end of the list and return its head. Example 1: Input: head = [1,2,3,4,5], n = 2 Output: [1,2,3,5] Example 2: Input: head = [1], n = 1 Output: [] Example 3: Input: head = [1,2], n = 1 Output: [1] Constraints: The number of nodes in the list is sz. 1 <= sz <= 30 0 <= Node.val <= 100 1 <= n <= sz Follow up: Could you do this in one pass?

Given an integer array nums, find a contiguous non-empty subarray within the array that has the largest product, and return the product. It is guaranteed that the answer will fit in a 32-bit integer. A subarray is a contiguous subsequence of the array. Example 1: Input: nums = [2,3,-2,4] Output: 6 Explanation: [2,3] has the largest product 6. Example 2: Input: nums = [-2,0,-1] Output: 0 Explanation: The result cannot be 2, because [-2,-1] is not a subarray. Constraints: 1 <= nums.length <= 2 * 104 -10 <= nums[i] <= 10 The product of any prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

A trie (pronounced as "try") or prefix tree is a tree data structure used to efficiently store and retrievekeys in a dataset of strings. There are various applications of this data structure,such as autocomplete and spellchecker. Implement the Trie class: Trie() Initializes the trie object.void insert(String word) Inserts the string word into the trie.boolean search(String word) Returns true if the string word is in the trie (i.e., was nserted before),and false otherwise.boolean startsWith(String prefix) Returns true if there is a previously inserted string ord that hasthe prefix prefix, and false otherwise.  Example 1: Input["Trie", "insert", "search", "search", "startsWith", "insert", "search"][[], ["apple"], ["apple"], ["app"], ["app"], ["app"], ["app"]]Output[null, null, true, false, true, null, true] ExplanationTrie trie = new Trie();trie.insert("apple");trie.search("apple");   // return Truetrie.search("app");     // return Falsetrie.startsWith("app"); // return Truetrie.insert("app");trie.search("app");     // return True  Constraints: 1 <= word.length, prefix.length <= 2000word and prefix consist only of lowercase English letters.At most 3 * 104 calls in total will be made to insert, search, and startsWith.

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