题目原文: You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. Input: (2 -> 4 -> 3) + (5 -> 6…

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 contain a single digit. Add the two numbers and return it as a linked list. You may assume the two numbers…

注意进位的处理和节点为null的处理 public ListNode addTwoNumbers(ListNode l1, ListNode l2) { int flag = 0; ListNode res = null; ListNode temp = null; //注意如果进位不是0的话还要添加一个节点 while (l1!=null||l2!=null||flag!=0) { int cur = flag; flag = 0; if (l1!=null) { cur+=l1.val; l…

题目难度:Medium 题目: Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target. Note: The solution set must not contain duplicate quadrup…

题目: Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. 翻译: 给定一组整数,两个数字的返回索引,它们的和会等于一个特定…

题目: Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. 翻译: 给定一组整数,两个数字的返回索引,它们的和会等于一个特定…

题目:求所有全排列 难度:Medium 题目内容: Given a collection of distinct integers, return all possible permutations. 翻译:给定一组各不相同的整数,返回所有可能的排列. Example: Input: [1,2,3] Output: [ [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1] ] 我的思路:每种情况中,每一个元素只出现一次,只是之间的顺序不同,那么…

题目:数组加一 难度:Easy 题目内容:   Given a non-empty array of digits representing a non-negative integer, plus one to the integer. The digits are stored such that the most significant digit is at the head of the list, and each element in the array contain a sin…

题目难度:Medium 题目: 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 contain a single digit. Add the two numbers and return it as a linked list. You may assume…

题目: 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 contain a single digit. Add the two numbers and return it as a linked list. You may assume the two num…