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Leetcode 1986: Minimum Number of Work Sessions to Finish the Tasks

You are assigned several tasks, each with a specified time required to complete. A work session allows you to work continuously for up to sessionTime consecutive hours before taking a break. Your goal is to determine the minimum number of work sessions required to complete all tasks under the following conditions:

  • If a task is started in a session, it must be completed within that same session.
  • You may complete the tasks in any order.
  • You can begin a new task immediately after finishing the previous one.

Return the minimum number of work sessions needed to complete all tasks.

Apr 22, 2024 - 8 min read

Leetcode 1991: Find the Middle Index in Array

Given a 0-indexed integer array ’nums’, find the leftmost index where the sum of elements to the left of that index is equal to the sum of elements to the right of that index. If such an index exists, return the smallest such index, otherwise return -1. The sum of the elements before the first index is considered 0, and similarly, the sum of elements after the last index is also 0.

Apr 21, 2024 - 5 min read

Leetcode 1992: Find All Groups of Farmland

You are given an m x n binary matrix representing a piece of land, where ‘1’ denotes farmland and ‘0’ denotes forest. Your task is to identify the coordinates of each rectangular group of contiguous farmland (1’s), where each group of farmland is isolated and not adjacent to another group. Return a list of 4-length arrays, where each array represents the top-left and bottom-right coordinates of a rectangular farmland group.

Apr 21, 2024 - 7 min read

Leetcode 1993: Operations on Tree

You are given a tree with n nodes numbered from 0 to n - 1 represented by a parent array. You need to implement the LockingTree class with methods for locking, unlocking, and upgrading nodes in the tree based on certain conditions.

Apr 21, 2024 - 8 min read

Leetcode 1995: Count Special Quadruplets

Given a 0-indexed integer array ’nums’, return the number of distinct quadruplets (a, b, c, d) such that:

  • nums[a] + nums[b] + nums[c] == nums[d], and
  • a < b < c < d.

Apr 21, 2024 - 5 min read

Leetcode 1996: The Number of Weak Characters in the Game

You are given a list of characters’ properties, where each character has two main attributes: attack and defense. A character is weak if another character exists with both greater attack and defense values. Return the number of weak characters in the list.

Apr 21, 2024 - 5 min read