Step-BY-Step

摘要： Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephon... 阅读全文

摘要： Given a linked list, remove thenthnode from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After re... 阅读全文

摘要： Given a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid.The brackets must close in the correct ... 阅读全文

摘要： Mergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity.第一遍： 1 public class Solution { 2 public ListNode m... 阅读全文