Machine Learning, AI and Programming

Tag: Breadth First Search

LeetCode: Word Ladder II

Problem Statement Solution: This is one of the problems asked frequently in coding interviews but has a relatively straighforward solution once one can get hold of the data-structures that he/she is going to implement. The idea is pretty simple, starting from 'beginWord', find out all possible words that are 1-distance away and also in the list of valid words. Repeat this step until we hit the 'endWord'. But since the […]

Continue Reading →

LeetCode : Bus Routes

Problem Statement Solution : Observe that one can switch from one route to another route, if both the routes have at-least one stop in common. Starting with the source stop S, there could be multiple possible bus routes R that includes this stop. Thus for every possible route R that include the stop S, do a Breadth First Search to all possible routes R' reachable from this route. R' can […]

Continue Reading →

LeetCode : Swim in Rising Water

Problem Statement Solution : One possible solution is to see whether for each water level, he can swim from (0, 0) to (N-1, N-1) without waiting anywhere in between. To check whether he can swim fromĀ (0, 0) to (N-1, N-1) i.e. there exists a path, we can use DFS or BFS to traverse the matrix. He can swim from point A to B if the height of B is less […]

Continue Reading →