A full binary tree is a binary tree where each node has exactly 0 or 2 children. Return a list of all possible full binary trees with N nodes. Each e ...

Given a directed, acyclic graph of N nodes. Find all possible paths from node 0 to node N-1, and return them in any order. The graph is given as foll ...

Given a string S of ‘(‘ and ‘)’ parentheses, we add the minimum number of parentheses ( ‘(‘ or ‘)’, and in any positions ) so that the resulting paren ...

You have a list of words and a pattern, and you want to know which words in words matches the pattern. A word matches the pattern if there exists a pe ...

In a 2 dimensional array grid, each value grid[i][j] represents the height of a building located there. We are allowed to increase the height of any n ...

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation. Note The given integ ...

Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You mi ...

You’re now a baseball game point recorder. Given a list of strings, each string can be one of the 4 following types: Integer (one round’s score): Dir ...

Alice and Bob have candy bars of different sizes: A[i] is the size of the i-th bar of candy that Alice has, and B[j] is the size of the j-th bar of ca ...

We are given two sentences A and B. (A sentence is a string of space separated words. Each word consists only of lowercase letters.) A word is uncom ...