[BOJ] 14267 회사 문화1Read more
[Hacker Rank] String Function CalculationRead more
[LeetCode] Design Circular Deque

641. Design Circular Deque

Design your implementation of the circular double-ended queue (deque).

Implement the MyCircularDeque class:

  • MyCircularDeque(int k) Initializes the deque with a maximum size of k.
  • boolean insertFront() Adds an item at the front of Deque. Returns true if the operation is successful, or false otherwise.
  • boolean insertLast() Adds an item at the rear of Deque. Returns true if the operation is successful, or false otherwise.
  • boolean deleteFront() Deletes an item from the front of Deque. Returns true if the operation is successful, or false otherwise.
  • boolean deleteLast() Deletes an item from the rear of Deque. Returns true if the operation is successful, or false otherwise.
  • int getFront() Returns the front item from the Deque. Returns -1 if the deque is empty.
  • int getRear() Returns the last item from Deque. Returns -1 if the deque is empty.
  • boolean isEmpty() Returns true if the deque is empty, or false otherwise.
  • boolean isFull() Returns true if the deque is full, or false otherwise.
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[LeetCode] Max Consecutive Ones II

487. Max Consecutive Ones II

Given a binary array nums, return the maximum number of consecutive 1’s in the array if you can flip at most one 0.

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[LeetCode] Increasing Order Search Tree

897. Increasing Order Search Tree

Given the root of a binary search tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only one right child.

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[LeetCode] Design an ATM Machine

2241. Design an ATM Machine

There is an ATM machine that stores banknotes of 5 denominations: 20, 50, 100, 200, and 500 dollars. Initially the ATM is empty. The user can use the machine to deposit or withdraw any amount of money.

When withdrawing, the machine prioritizes using banknotes of larger values.

  • For example, if you want to withdraw $300 and there are 2 $50 banknotes, 1 $100 banknote, and 1 $200 banknote, then the machine will use the $100 and $200 banknotes.
  • However, if you try to withdraw $600 and there are 3 $200 banknotes and 1 $500 banknote, then the withdraw request will be rejected because the machine will first try to use the $500 banknote and then be unable to use banknotes to complete the remaining $100. Note that the machine is not allowed to use the $200 banknotes instead of the $500 banknote.

Implement the ATM class:

  • ATM() Initializes the ATM object.
  • void deposit(int[] banknotesCount) Deposits new banknotes in the order $20, $50, $100, $200, and $500.
  • int[] withdraw(int amount) Returns an array of length 5 of the number of banknotes that will be handed to the user in the order $20, $50, $100, $200, and $500, and update the number of banknotes in the ATM after withdrawing. Returns [-1] if it is not possible (do not withdraw any banknotes in this case).
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[LeetCode] Maximum Score of a Node Sequence

2242. Maximum Score of a Node Sequence

There is an undirected graph with n nodes, numbered from 0 to n - 1.

You are given a 0-indexed integer array scores of length n where scores[i] denotes the score of node i. You are also given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.

A node sequence is valid if it meets the following conditions:

  • There is an edge connecting every pair of adjacent nodes in the sequence.
  • No node appears more than once in the sequence.

The score of a node sequence is defined as the sum of the scores of the nodes in the sequence.

Return the maximum score of a valid node sequence with a length of 4. If no such sequence exists, return -1.

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[LeetCode] Minimum Rounds to Complete All Tasks

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.

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[LeetCode] Calculate Digit Sum of a String

2243. Calculate Digit Sum of a String

You are given a string s consisting of digits and an integer k.

A round can be completed if the length of s is greater than k. In one round, do the following:

  1. Divide s into consecutive groups of size k such that the first k characters are in the first group, the next k characters are in the second group, and so on. Note that the size of the last group can be smaller than k.
  2. Replace each group of s with a string representing the sum of all its digits. For example, “346” is replaced with “13” because 3 + 4 + 6 = 13.
  3. Merge consecutive groups together to form a new string. If the length of the string is greater than k, repeat from step 1.

Return s after all rounds have been completed.

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[LeetCode] Maximum Trailing Zeros in a Cornered Path

2245. Maximum Trailing Zeros in a Cornered Path

You are given a 2D integer array grid of size m x n, where each cell contains a positive integer.

A cornered path is defined as a set of adjacent cells with at most one turn. More specifically, the path should exclusively move either horizontally or vertically up to the turn (if there is one), without returning to a previously visited cell. After the turn, the path will then move exclusively in the alternate direction: move vertically if it moved horizontally, and vice versa, also without returning to a previously visited cell.

The product of a path is defined as the product of all the values in the path.

Return the maximum number of trailing zeros in the product of a cornered path found in grid.

Note:

  • Horizontal movement means moving in either the left or right direction.
  • Vertical movement means moving in either the up or down direction.
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