https://leetcode.com/problems/all-ancestors-of-a-node-in-a-directed-acyclic-graph/description/

List of ancestors in a DAG #medium #dfs #toposort

https://leetcode.com/problems/remove-max-number-of-edges-to-keep-graph-fully-traversable/description/

Remove extra nodes in a connected graph by type 1, 2 and 3=1+2 #hard #union-find

https://leetcode.com/problems/three-consecutive-odds/description/

Has window of 3 odds? #easy

https://leetcode.com/problems/intersection-of-two-arrays-ii/description/

Array intersection with duplicates #easy

https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves/description/

Min difference after 3 changes in array #medium #sliding_window #dynamic_programming

https://leetcode.com/problems/merge-nodes-in-between-zeros/description/

Collapse in-between 0 nodes in a LinkedList #medium #linked_list

https://leetcode.com/problems/find-the-minimum-and-maximum-number-of-nodes-between-critical-points/description/

[min, max] distance between critical points in linked list #medium #linked_list

https://leetcode.com/problems/pass-the-pillow/description/

Loop position in increasing-decreasing array #easy #math #simulation

https://leetcode.com/problems/water-bottles/description/

Bottles drink and exchange simulation #easy #math #simulation

https://leetcode.com/problems/find-the-winner-of-the-circular-game/description/

Last of k-th excluded from 1..n #medium #simulation #math

https://leetcode.com/problems/crawler-log-folder/description/

Filesystem path depth #easy

https://leetcode.com/problems/reverse-substrings-between-each-pair-of-parentheses/description/

Reverse string in parentheses recursively #medium

https://leetcode.com/problems/maximum-score-from-removing-substrings/description/

Max score removing from s, x for ab, y for ba #medium #greedy #stack

https://leetcode.com/problems/robot-collisions/description/

1-D dimensional robots fight #hard #stack

https://leetcode.com/problems/number-of-atoms/description/

Simplify chemical formula parenthesis #hard #stack

https://leetcode.com/problems/create-binary-tree-from-descriptions/description/

Restore binary tree from [parent, child, isLeft] #medium

https://leetcode.com/problems/step-by-step-directions-from-a-binary-tree-node-to-another/description/

U-L-R path from s to d in a Binary Tree #medium #tree

https://leetcode.com/problems/delete-nodes-and-return-forest/description/

Trees after remove nodes from tree #medium #tree

https://leetcode.com/problems/number-of-good-leaf-nodes-pairs/description/

Count at most distance paths between leafs #medium #tree

https://leetcode.com/problems/lucky-numbers-in-a-matrix/description/

Min in rows and max in columns in a unique number matrix #easy