문제 Design your implementation of the linked list. You can choose to use a singly or doubly linked list. A node in a singly linked list should have two attributes: val and next. val is the value of the current node, and next is a pointer/reference to the next node. If you want to use the doubly linked list, you will need one more attribute prev to indicate the previous node in the linked list. As..

문제 There is an authentication system that works with authentication tokens. For each session, the user will receive a new authentication token that will expire timeToLive seconds after the currentTime. If the token is renewed, the expiry time will be extended to expire timeToLive seconds after the (potentially different) currentTime. Implement the AuthenticationManager class: AuthenticationManag..

문제 You are given a nested list of integers nestedList. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an iterator to flatten it. Implement the NestedIterator class: NestedIterator(List nestedList) Initializes the iterator with the nested list nestedList. int next() Returns the next integer in the nested list. boolean hasNext() Returns tr..

문제 Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. Implement the MinStack class: MinStack() initializes the stack object. void push(int val) pushes the element val onto the stack. void pop() removes the element on the top of the stack. int top() gets the top element of the stack. int getMin() retrieves the minimum element in the stack. You must i..

문제 Design a system that manages the reservation state of n seats that are numbered from 1 to n. Implement the SeatManager class: SeatManager(int n) Initializes a SeatManager object that will manage n seats numbered from 1 to n. All seats are initially available. int reserve() Fetches the smallest-numbered unreserved seat, reserves it, and returns its number. void unreserve(int seatNumber) Unrese..

https://leetcode.com/problems/add-two-numbers-ii/ Add Two Numbers II - LeetCode Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 문제 You are given two non-empty linked lists representing two non-negative integers. The most significant digit comes first and each of their nodes contains a singl..

https://leetcode.com/problems/add-two-numbers/ Add Two Numbers - LeetCode Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 문제 You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single dig..

문제 https://leetcode.com/problems/copy-list-with-random-pointer/ Copy List with Random Pointer - LeetCode Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com A linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, o..