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Practice › LeetCode › LeetCode (archived) › LeetCode 07xx ›

LeetCode 743: Network Delay Time

Problem Restatement We are given a directed weighted graph with n nodes labeled from 1 to n . The input times contains directed edges: [u, v, w] This means a signal can travel from node u to node v in w time. A signal starts from node k . We need to return the minimum time needed for all nodes to receive the signal. If some node cannot receive the...

Practice › LeetCode › LeetCode (archived) › LeetCode 08xx ›

LeetCode 882: Reachable Nodes In Subdivided Graph

Problem Restatement We are given an undirected graph with original nodes numbered from 0 to n - 1 . Each edge is written as: [u, v, cnt] This means the original edge between u and v is subdivided by adding cnt new nodes between them. For example: [0, 1, 3] becomes: 0 - x1 - x2 - x3 - 1 So moving from 0 to 1 through this edge takes...

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LeetCode 778: Swim in Rising Water

Problem Restatement We are given an n x n grid. Each cell grid[i][j] is the elevation of that square. Rain starts falling. At time t , the water level is also t . We can swim from one cell to a 4-directionally adjacent cell only if both cells have elevation at most t . We start at the top-left cell: (0, 0) We want to reach the bottom-right cell: (n...

Practice › LeetCode › LeetCode (archived) › LeetCode 05xx ›

LeetCode 505: The Maze II

Problem Restatement We are given a maze represented as a grid. Value Meaning 0 Empty space 1 Wall A ball starts at position start . The goal is to reach position destination . The ball does not move one cell at a time. Instead, once the ball starts moving in a direction, it keeps rolling until it hits a wall. Only then can it choose another direction. We need to...

Practice › LeetCode › LeetCode (archived) › LeetCode 04xx ›

LeetCode 499: The Maze III

Problem Restatement We are given a maze represented by a 2D grid. Value Meaning 0 Empty cell 1 Wall A ball starts at ball . There is also a hole at hole . The ball can roll in four directions: Letter Direction u Up d Down l Left r Right Once the ball starts rolling, it keeps moving in that direction until one of two things happens: It hits a...

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LeetCode 743: Network Delay Time

LeetCode 882: Reachable Nodes In Subdivided Graph

LeetCode 778: Swim in Rising Water

LeetCode 505: The Maze II

LeetCode 499: The Maze III