[Codeforces] Round #816 (Div. 2) C. MonoblockRead more
[Codeforces] Round #817 (Div. 4) F. L-shapesRead more
[Codeforces] Round #841 (Div. 2) and Divide by Zero 2022 C. Even SubarraysRead more
[Codeforces] Round #841 (Div. 2) and Divide by Zero 2022 D. Valiant`s New MapRead more
[LeetCode] Difference Between Element Sum and Digit Sum of an Array

2535. Difference Between Element Sum and Digit Sum of an Array

You are given a positive integer array nums.

  • The element sum is the sum of all the elements in nums.
  • The digit sum is the sum of all the digits (not necessarily distinct) that appear in nums.

Return the absolute difference between the element sum and digit sum of nums.

Note that the absolute difference between two integers x and y is defined as |x - y|.

Read more
[LeetCode] Count the Number of Good Subarrays

2537. Count the Number of Good Subarrays

Given an integer array nums and an integer k, return the number of good subarrays of nums.

A subarray arr is good if it there are at least k pairs of indices (i, j) such that i < j and arr[i] == arr[j].

A subarray is a contiguous non-empty sequence of elements within an array.

Read more
[LeetCode] Increment Submatrices by One

2536. Increment Submatrices by One

You are given a positive integer n, indicating that we initially have an n x n 0-indexed integer matrix mat filled with zeroes.

You are also given a 2D integer array query. For each query[i] = [row1i, col1i, row2i, col2i], you should do the following operation:

  • Add 1 to every element in the submatrix with the top left corner (row1i, col1i) and the bottom right corner (row2i, col2i). That is, add 1 to mat[x][y] for for all row1i <= x <= row2i and col1i <= y <= col2i.

Return the matrix mat after performing every query.

Read more
[LeetCode] Difference Between Maximum and Minimum Price Sum

2538. Difference Between Maximum and Minimum Price Sum

There exists an undirected and initially unrooted tree with n nodes indexed from 0 to n - 1. You are given the integer n and a 2D integer array edges of length n - 1, where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree.

Each node has an associated price. You are given an integer array price, where price[i] is the price of the ith node.

The price sum of a given path is the sum of the prices of all nodes lying on that path.

The tree can be rooted at any node root of your choice. The incurred cost after choosing root is the difference between the maximum and minimum price sum amongst all paths starting at root.

Return the maximum possible cost amongst all possible root choices.

Read more
[AtCoder] B - Colorful HatsRead more
[AtCoder] D - 11Read more