You are given a list of accounts, where each account consists of a name and a list of emails. Merge accounts that share common emails, and return the merged accounts in the format: name followed by sorted emails.
You are given an m x n grid representing an image, where each element in the grid corresponds to a pixel value. Additionally, you’re provided with three integers: sr (starting row), sc (starting column), and color. Your task is to perform a flood fill operation on the image starting at the pixel located at (sr, sc).
You are given a network of n nodes and a list of directed edges with travel times. You need to send a signal from a given node k. Return the minimum time it takes for all nodes to receive the signal, or return -1 if it is impossible.
You are given a lock with 4 rotating wheels, each containing 10 slots labeled ‘0’ to ‘9’. The wheels can rotate freely and wrap around. You must determine the minimum number of moves required to reach a target lock configuration, avoiding certain deadends.
You are building a pyramid by stacking blocks, each represented by a color denoted by a letter. Each row above the bottom consists of one less block, centered on the row beneath. Only specific triangular patterns of blocks are allowed. A triangular pattern consists of three blocks: two at the bottom and one on top. Given the bottom row and allowed patterns, determine if it’s possible to construct the pyramid.
You are given an undirected graph where each node is labeled between 0 and n - 1. The graph is represented as a 2D array, where graph[u] contains the nodes that are adjacent to node u. A graph is bipartite if its nodes can be divided into two sets such that every edge connects a node from one set to a node in the other set. Your task is to return true if the graph is bipartite, otherwise return false.
