Trees and Graphs - Top Interview Questions[Hard] (4/9) - Python

Trees and Graphs

Tree is a special type of graphs, so the two usual techniques used to traverse a graph are also applicable to trees.

We recommend: Word Ladder, Lowest Common Ancestor of a Binary Tree, Course Schedule, Longest Increasing Path in a Matrix and Alien Dictionary.

Note that some of the tree problems can also be asked in n-ary tree format, so make sure you know what an n-ary tree is.

Note: The last problem may be quite tricky to solve, so feel free to skip that one.

 

 Word Ladder

 

 Surrounded Regions

 

 Lowest Common Ancestor of a Binary Tree

 

 Binary Tree Maximum Path Sum

 

 Friend Circles

 

 Course Schedule

 

 Course Schedule II

 

 Longest Increasing Path in a Matrix

 

 

 Alien Dictionary

 

 Count of Smaller Numbers After Self

 

 

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leetcode.com/problems/word-ladder/solution/

 

 

 

 

 

leetcode.com/problems/surrounded-regions/solution/

 

 

 

leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/solution/

 

 

 

 

 

leetcode.com/problems/binary-tree-maximum-path-sum/solution/

 

 

 

 

leetcode.com/problems/number-of-provinces/solution/

 

 

 

 

 

leetcode.com/problems/course-schedule/solution/

 

 

 

 

 

leetcode.com/problems/course-schedule-ii/solution/

 

 

 

 

 

leetcode.com/problems/longest-increasing-path-in-a-matrix/solution/

 

 

 

 

leetcode.com/problems/alien-dictionary/solution/

 

 

 

 

leetcode.com/problems/count-of-smaller-numbers-after-self/