题目描述: 解题思路: 反转的方法很简单,重点在于判断溢出的问题,下面给出了两种方法. Java代码: 方法一: 判断溢出方法:在执行完int newResult=result*10+tail语句后,紧接着进行逆运算result=(newResult-tail)/10,如果出现溢出,那么逆运算后result和newResult必然不相等,反之,如果没有溢出,则逆运算后result=newResult. public class LeetCode7 { public static void mai…

六月箴言 万物之中,希望最美:最美之物,永不凋零.—— 斯蒂芬·金 第二周算法记录 007 -- Reverse Integer (整数反转) 题干英文版: Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123Output: 321 Example 2: Input: -123Output: -321 Example 3: Input: 120Output: 21 Note:Assum…

Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 总结:处理整数溢出的方法 ①用数据类型转换long  或 long long ②在每次循环时先保存下数字变化之前的值,处理后单步恢复看是否相等 (比③好) ③整体恢复,看数字是否相等. 思路:注意30000这样以0结尾的数字,注意越界时返回0. 我检查越界是通过把翻转的数字再翻转回去,看是否相等. int rever…

题目描述: Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 很简单的题目其实用个数组就能解决了,不过用了一下queue,注意负数的情况. class Solution { public: int reverse(int x) { bool flg=false; ){ flg=true; x=-x; } queue<int> a; ){ a.push(x%); x…

Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the integer's…

思路:取绝对值,反转,并判断反转的结果是否大于最大整数,需要注意的细节:判断时需要这样:result > (Integer.MAX_VALUE - v) / 10 否则result * 10 + v% 10 > Integer.MAX_VALUE左边会直接出现溢出.最后加上符号位. public int reverse(int x) { if(x==Integer.MIN_VALUE){ return 0; } //然后取绝对值,判断绝对值不大于Integer.MAX_VALUDE,不能直接用…

这道题是LeetCode里的第7道题. 题目描述: 给出一个 32 位的有符号整数,你需要将这个整数中每位上的数字进行反转. 示例 1: 输入: 123 输出: 321  示例 2: 输入: -123 输出: -321 示例 3: 输入: 120 输出: 21 注意: 假设我们的环境只能存储得下 32 位的有符号整数,则其数值范围为 [−231,  231 − 1].请根据这个假设,如果反转后整数溢出那么就返回 0. 首先,这是一道简单题,根据我多年的做题经验来看,这道题肯定有坑,绝对会有 IN…

[LeetCode]397. Integer Replacement 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/integer-replacement/description/ 题目描述: Given a positive integer n and you can do operations as follow: If n is even, replace n with n/2. If n is odd, you…

Reverse Integer 题目要求:给定一个int 类型值,求值的反转,例如以下: Example1: x = 123, return 321      Example2: x = -123, return -321 简单问题一般蕴含细节的处理.思路非常easy,直接贴Java程序: public class Solution { public int reverse(int x) { int head = x/10; int tail = x%10; long re = 0; while…

LeetCode第7题: Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note:Assume we are dealing with an environment which could only store int…

Given a 32-bit signed integer, reverse digits of an integer. Example 1:                               Input: 123                       Output: 321 Example 2:                               Input: -123                      Output: -321 Example 3:     …

Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 click to show spoilers. Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought throu…

Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the integer's…

Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 解题:设定一个变量sum存放反转后的答案,每次取输入x的最后一位n,并用sum = sum*10+n更新sum. 例如题设的数字123,初始sum为0,过程如下: 取末尾的3,sum=3,x=12 取末尾的2,sum=32,x=1 取末尾的1,sum=321,x=0 特别注意x一开始就是0的处理,直接返回0就可以了.…

题目描述: 写一个函数,实现输入一个字符串,然后把其中的元音字母倒叙 注意 元音字母包含大小写,元音字母有五个a,e,i,o,u 原文描述: Write a function that takes a string as input and reverse only the vowels of a string. Example 1: Given s = "hello", return "holle". Example 2: Given s = "leet…

Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000). 思路: n一直右移, ans一直左移. class So…

Reverse Nodes in k-Group 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 nodes in the end should remain as it is. You may not alter the valu…

Reverse Linked List II Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note:Given m, n satisfy the following cond…

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 nodes in the end should remain as it is. You may not alter the values in the nodes, only nod…

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. 思路: 好困啊,脑子晕晕的. 转了半天AC了.但写的很罗嗦,要学习大神的写法. 注意翻转的写法. 用伪头部 大神14行简洁代码 L…

Reverse a singly linked list. 思路:没啥好说的.秒... ListNode* reverseList(ListNode* head) { ListNode * rList = NULL, * tmp = NULL; while(head != NULL) { tmp = rList; rList = head; head = head->next; rList->next = tmp; } return rList; }…

Given an input string, reverse the string word by word. For example,Given s = "the sky is blue",return "blue is sky the". For C programmers: Try to solve it in-place in O(1) space. Clarification: What constitutes a word?A sequence of n…

今天第一次在leetcode上提交了一个题目,据说这个网站基本上都是名企面试笔试题,今天无意一进去就看到第一题居然就是昨天的腾讯实习生笔试题,赶紧注册了个账号做题. 题目描述: Given an input string, reverse the string word by word. For example,Given s = "the sky is blue",return "blue is sky the".   很简单的英文就不翻译了.题目不难但是做这个题…

本来没想出来,刚才突然想到,可以用“头插法”来反转 Reverse Linked List My Submissions Question Total Accepted: 66556 Total Submissions: 182891 Difficulty: Easy Reverse a singly linked list. click to show more hints. Discuss中的递归解法: public ListNode reverseList(ListNode head) {…

Integer to English Words Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 231 - 1. For example, 123 -> "One Hundred Twenty Three" 12345 -> "Twelve Thousand Three Hundred For…

题目: Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 思路: 主要是了解罗马数和阿拉伯数字的对应关系,如下表: 由这个表基本上可以将1-3999范围的阿拉伯数字换成罗马数字.在处理阿拉伯数字时从高位开始匹配,将每个位的值找出对应罗马数字,串成字符串即可. public class Solution { public String…

题目描述: Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 解题思路: 注意到用例比较少,所以采用以空间换时间的方法,把所有的结果列出,然后组合出输入值n的字符串即可. 具体代码: public class Solution { public static String intToRoman(int num) { String[]…

reverse函数的功能是反转排序一个容器中指定元素的内容. 函数参数:reverse(first,last), 其中first,last分别指向被反转序列中初始及末尾位置的双向迭代器(Bidirectional iterators).这个范围即 [first,last) ,包括 first 到 last 间的所有元素,包括 first 指向的元素,但不包括 last 指向的元素. 无返回值 示例: #include <iostream> #include <list> names…

转自:http://www.tuicool.com/articles/AraaQbZ 论integer是地址传递还是值传递 Integer 作为传参的时候是地址传递 , 可以参考如下例子,在程序刚启动的时候把 Integer 的index 对象锁住 ,并且调用了 wait方法,释放了锁的资源,等待notify,最后过了5秒钟,等待testObject 调用notify 方法就继续执行了.大家都知道锁的对象和释放的对象必须是同一个,否则会抛出  java.lang.IllegalMonitorSt…

The K−P factorization of a positive integer N is to write N as the sum of the P-th power of K positive integers. You are supposed to write a program to find the K−P factorization of N for any positive integers N, K and P. Input Specification: Each in…