## Leetcode 2244: Minimum Rounds to Complete All Tasks

You are given a 0-indexed integer array tasks, where tasks[i] represents the difficulty level of a task. In each round, you can complete either 2 or 3 tasks of the same difficulty level. Return the minimum rounds required to complete all the tasks, or -1 if it is not possible to complete all the tasks. Example 1: <strong>Input:</strong> tasks = [2,2,3,3,2,4,4,4,4,4] <strong>Output:</strong> 4 <strong>Explanation:</strong> To complete ...

## Leetcode 944: Delete Columns to Make Sorted

You are given an array of n strings strs, all of the same lengths. The strings can be arranged such that there is one on each line, making a grid. For example, strs = ["abc", "bce", "cae"] can be arranged as: abc bce cae You want to <strong>delete</strong> the columns that are <strong>not sorted lexicographically</strong>. In the above example (0-indexed), columns 0 (<code>'a'</code>, <code>'b'</code>, <code>'c'</code>) ...

## Solved! Leetcode 520: Detect Capital

We define the usage of capitals in a word to be right when one of the following cases holds: All letters in this word are capitals, like "USA". All letters in this word are not capitals, like "leetcode". Only the first letter in this word is capitalized, like "Google". Given a string “word”, return true if the usage of capitals ...

## Leetcode 379: Design Phone Directory

Design a phone directory that initially has maxNumbers empty slots that can store numbers. The directory should store numbers, check if a certain slot is empty or not, and empty a given slot. Implement the PhoneDirectory class: PhoneDirectory(int maxNumbers) Initializes the phone directory with the number of available slots maxNumbers.int get() Provides a number that ...

You are given an integer length and array updates where updates[i] = [startIdxi, endIdxi, inci]. You have an array “arr” of length with all zeros, and you have some operation to apply on arr. In the ith operation, you should increment all the elements arr[startIdxi], arr[startIdxi + 1], …, arr[endIdxi] by inci. Return arr after ...

## Leetcode 1056: Confusing Number

A confusing number is a number that, when rotated 180 degrees, becomes a different number with each digit valid. We can rotate the digits of a number by 180 degrees to form new digits. When 0, 1, 6, 8, and 9 are rotated 180 degrees, they become 0, 1, 9, 8, and 6, respectively.When 2, ...

## Leetcode 290: Word Pattern

Given a pattern and a string s, find if s follows the same pattern. Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in s. https://leetcode.com/problems/word-pattern/ class Solution { public boolean wordPattern(String pattern, String s) { String[] sArr = s.split(" "); Map<Character, String> map = new HashMap<>(); char[] pArr = pattern.toCharArray(); //if the length of ...

## Solved! Leetcode 1428: Leftmost Column with at Least a One

A row-sorted binary matrix means that all elements are 0 or 1 and each row of the matrix is sorted in non-decreasing order.Given a row-sorted binary matrix binaryMatrix, return the index (0-indexed) of the leftmost column with a 1 in it. If such an index does not exist, return -1.You can’t access the Binary Matrix ...

## Leetcode 797: All Paths From Source to Target

Given a directed acyclic graph (DAG) of n nodes labeled from 0 to n - 1, find all possible paths from node 0 to node n - 1 and return them in any order. The graph is given as follows: graph[i] is a list of all nodes you can visit from node i (i.e., there is a directed edge from node i to node graph[i][j]). https://leetcode.com/problems/all-paths-from-source-to-target/description/ class Solution { public List<List<Integer>> allPathsSourceTarget(int[][] ...

## Leetcode 1167: Minimum Cost to Connect Sticks

You have some number of sticks with positive integer lengths. These lengths are given as an array sticks, where sticks[i] is the length of the ith stick. You can connect any two sticks of lengths x and y into one stick by paying a cost of x + y. You must connect all the sticks until there is only one stick remaining. Return the minimum cost of connecting ...