摘要:
Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. Example: 阅读全文
摘要:
Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: No 阅读全文
摘要:
Given a linked list, remove the n-th node from the end of list and return its head. Example: Note: Given n will always be valid. Follow up: Could you 阅读全文
摘要:
Given an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c + d = target? Find all unique q 阅读全文