[AtCoder] D - Grid ColoringRead more
[AtCoder] C - 4-adjacentRead more
[Codeforces] Round #724 (Div. 2) C. Diluc and KaeyaRead more
[Codeforces] Round #725 (Div. 3) F. Interesting FunctionRead more
[Codeforces] Plus and MultiplyRead more
[Codeforces] Round #732 (Div. 1) A. AquaMoon and Strange SortRead more
[Codeforces] Round #731 (Div. 3) E. Air ConditionersRead more
[LeetCode] Depth of BST Given Insertion Order

1902. Depth of BST Given Insertion Order

You are given a 0-indexed integer array order of length n, a permutation of integers from 1 to n representing the order of insertion into a binary search tree.

A binary search tree is defined as follows:

  • The left subtree of a node contains only nodes with keys less than the node’s key.
  • The right subtree of a node contains only nodes with keys greater than the node’s key.
  • Both the left and right subtrees must also be binary search trees.

The binary search tree is constructed as follows:

  • order[0] will be the root of the binary search tree.
  • All subsequent elements are inserted as the child of any existing node such that the binary search tree properties hold.

Return the depth of the binary search tree.

A binary tree’s depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

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[LeetCode] Game of Nim

1908. Game of Nim

Alice and Bob take turns playing a game with Alice starting first.

In this game, there are n piles of stones. On each player’s turn, the player should remove any positive number of stones from a non-empty pile of his or her choice. The first player who cannot make a move loses, and the other player wins.

Given an integer array piles, where piles[i] is the number of stones in the ith pile, return true if Alice wins, or false if Bob wins.

Both Alice and Bob play optimally.

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[LeetCode] Largest Magic Square

1895. Largest Magic Square

A k x k magic square is a k x k grid filled with integers such that every row sum, every column sum, and both diagonal sums are all equal. The integers in the magic square do not have to be distinct. Every 1 x 1 grid is trivially a magic square.

Given an m x n integer grid, return the size (i.e., the side length k) of the largest magic square that can be found within this grid.

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