Be a Good Techer and Tech for Good. www.goodtecher.com
Description https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string/ You are given a string s consisting of lowercase English letters. A duplicate removal consists of choosing two adjacent and equal letters and removing them. We…
Description https://leetcode.com/problems/shortest-distance-to-target-color/ You are given an array colors, in which there are three colors: 1, 2 and 3. You are also given some queries. Each…
Description https://leetcode.com/problems/alphabet-board-path/ On an alphabet board, we start at position (0, 0), corresponding to character board[0][0]. Here, board = [“abcde”, “fghij”, “klmno”, “pqrst”,…
Description https://leetcode.com/problems/sum-of-beauty-in-the-array/ You are given a 0-indexed integer array nums. For each index i (1 <= i <= nums.length – 2) the beauty of nums[i] equals: 2, if nums[j] <…
Description https://leetcode.com/problems/final-value-of-variable-after-performing-operations/ There is a programming language with only four operations and one variable X: ++X and X++ increments the value of the variable X by 1. –X and X– decrements the value of the variable X by 1.…
Description https://leetcode.com/problems/unique-binary-search-trees/ Given an integer n, return the number of structurally unique BST’s (binary search trees) which has exactly n nodes of unique values from 1 to n.…
Description https://leetcode.com/problems/find-duplicate-subtrees/ Given the root of a binary tree, return all duplicate subtrees. For each kind of duplicate subtrees, you only need to…
Description https://leetcode.com/problems/license-key-formatting/ You are given a license key represented as a string s that consists of only alphanumeric characters and dashes. The…
Description https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree/ Given the root of a binary tree, the level of its root is 1, the level of its children is 2, and…
Description https://leetcode.com/problems/all-possible-full-binary-trees/ Given an integer n, return a list of all possible full binary trees with n nodes. Each node of each tree in the answer…