Given a string s and a dictionary of words wordDict, return true if s can be segmented into a space-separated sequence of one or more words from the dictionary. The same word in the dictionary can be reused multiple times.
Given the head of a linked list, determine if there is a cycle. A cycle occurs if a node can be revisited by following the ’next’ pointers. The ‘pos’ parameter denotes where the last node connects to. If ‘pos’ is -1, there is no cycle.
Given the head of a linked list, find the node where the cycle begins. If no cycle exists, return null. The list may contain a cycle, which occurs if a node can be revisited by following the ’next’ pointers continuously.
Design and implement an LRU (Least Recently Used) cache. The cache should support two operations: get(key) and put(key, value). Both operations must run in O(1) time on average. If the cache exceeds its capacity, the least recently used key should be evicted.
Given an array nums of size n, return the majority element. The majority element is the element that appears more than n // 2 times. You may assume that the majority element always exists in the array.
A happy number is a number that eventually reaches 1 when replaced by the sum of the squares of its digits. If the process results in an endless loop of numbers, the number is not happy. Your task is to determine whether a given number is a happy number.
