这个题确实太容易错了. 我已经做了2遍了,之前都是套用reverse List 1中的函数. 现在尝试用新方法,在一个函数里完成,结果又错了. 事实证明,永远不要想当然!!!白板编程真的是要求,你对每一行代码都知道在做什么!尤其是边界条件. 因为没有编译调试环境,写错了,你根本看不出来,没有修改的机会啊!! 要求一遍就过啊! 这太难了.看看我提交的这些题目,几个是一遍就过的???都是写完先跑一遍再说,有错再慢慢改!! 毛病啊!! struct ListNode* reverseBetween(s…

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. If the number of nodes is not a multiple of k then left-out no…

1.题目描述 Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order. Example 1: Input: "Let's take LeetCode contest" Output: "s'teL ekat edoCteeL tsetnoc…

Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there are less than k characters left, reverse all of them. If there are less than 2k but greater than or eq…

题目: 数字翻转,即输入123,返回321:输入-123,返回-321. 代码: class Solution { public: int reverse(int x) { , sign = ; ) //负数转换为正数统一处理 { x = -x; sign = -; } ) { result *= ; result += x % ; x /= ; } return result * sign; //返回时记得加上符号 } };…

problem: Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 thinking: (1)整型反转直观非常easy理解. 如正负,尾数为0等问题还优点理. (2)反转溢出问题要细致处理. code: class Solution { public: int reverse(int x) { long long int y=x; bool flag=true;…

Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example,[1,1,2] have the following unique permutations:[1,1,2], [1,2,1], and [2,1,1].题解:依旧使用的是DFS的思想. 首先需要遍历输入数组,获取一共有多少种不同的数字,每个数字有多少个. 最简单的方法,…

题目描述: Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times. The algorithm should run in linear time and in O(1) space. 分析: 因为要找出的是出现次数大于⌊ n/3 ⌋的元素,因此最多只可能存在两个这样的元素,而且要求O(1)的空间复杂度,因此只能使用摩尔投票法.首先我们遍历一遍数组找出两个候选元素,接着再遍历…

原题地址: 344 Reverse String: https://leetcode.com/problems/reverse-string/description/ 541 Reverse String II: https://leetcode.com/problems/reverse-string-ii/description/ 题目&&解法: 1.Reverse String: Write a function that takes a string as input and ret…

344. Reverse String 最基础的旋转字符串 class Solution { public: void reverseString(vector<char>& s) { if(s.empty()) return; ; ; while(start < end){ char tmp = s[end]; s[end] = s[start]; s[start] = tmp; start++; end--; } return; } }; 541. Reverse Strin…