题目链接: http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1810 题目大意: 一个长度为N的十进制数,R(i,j)表示将第i位到第j位翻转过来后的数字,求mod 109+7 题目思路: [数学] 这题换一种思路,看每个数字能够对答案的贡献情况.(可以手推01,10,001,010,100.....,也可以像我一样写个暴力打个10以内的表看看规律) 现在先考虑位置为i的数字为1的情况(最后乘上这个数字就行).可以发现贡献是对称的(第i位的1和第…

湖南省第十二届大学生计算机程序设计竞赛$H$题 规律,递推. 这种问题一看就有规律.可以按位统计对答案的贡献.即第$1$位对答案作出了多少贡献,第$2$位对答案作出了多少贡献.....累加和就是答案. 先写一个暴力的程序来找找规律: #pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cmath> #in…

Reverse digits of an integer. Example1: x = 123, return 321 Example2: 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'…

数组中存在的两个方法:sort()和reverse() 直接用sort(),如下: ,,,,,,,,,,,]; console.log(array.sort());ps:[0, 1, 2, 2, 29, 3, 3, 34, 7, 7, 782, 8] 这个好像真的效果,sort(): arr.sort([compareFunction]) 参数 compareFunction 可选.用来指定按某种顺序进行排列的函数.如果省略,元素按照转换为的字符串的诸个字符的Unicode位点进行排序. 原来是…

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 = "leetcode", return "leotcede". 这道题让我们翻转字符串中的元音字母,元音字母有五个a,e,i,o…

Write a function that takes a string as input and returns the string reversed. Example: Given s = "hello", return "olleh". 这道题没什么难度,直接从两头往中间走,同时交换两边的字符即可,参见代码如下: 解法一: class Solution { public: string reverseString(string s) { , right =…

Reverse a singly linked list. click to show more hints. Hint: A linked list can be reversed either iteratively or recursively. Could you implement both? 之前做到Reverse Linked List II 倒置链表之二的时候我还纳闷怎么只有二没有一呢,原来真是忘了啊,现在才加上,这道题跟之前那道比起来简单不少,题目为了增加些许难度,让我们分别用…

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). Follow up:If this function i…

Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.The input string does not contain leading or trailing spaces and the words are always separated by a single space.For example,Given s = "t…

Given an input string, reverse the string word by word. For example, Given s = "the sky is blue", return "blue is sky the". Update (2015-02-12): For C programmers: Try to solve it in-place in O(1) space. click to show clarification. Cl…

Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Some examples: ["2", "1", "+", "3", "*"] -&g…

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 condition:1 ≤ m ≤ n ≤ lengt…

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 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 public class Solution { public int reverse(int x) { if(x==Integer.MIN_VALUE) return 0; long result = 0; int i = 0; int temp = (x>0)?1:0; x = Math.abs(x); while…

Write a function that takes a string as input and reverse only the vowels(元音字母) of a string. Example 1:Given s = "hello", return "holle". Example 2:Given s = "leetcode", return "leotcede". Note:The vowels does not i…

Reverse a singly linked list. Hint: A linked list can be reversed either iteratively or recursively. Could you implement both? 递归的办法: /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { v…

数组的倒序排列,可以采用reverse()和pop()方法进行排列.…

问题描述: Given an input string, reverse the string word by word. For example,Given s = "the sky is blue",return "blue is sky the". 解题思路: 先利用split()方法将句子按空格分为几个单词的列表, 然后reverse()函数使列表逆序, 最后join函数以空格为间隔拼成字符串返回结果. Python代码: class Solution:  …

#206.  Reverse Linked List Reverse a singly linked list. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode* reverseList(ListNo…

#190. Reverse Bits Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000). 题解:移位运算.…

问题: 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…

问题: Reverse digits of an integer.Example1:x = 123, return 321Example2:x = -123, return -321 官方难度: Easy 翻译: 将一个整数倒转输出. 例子: 整数:123,倒转输出:321. 整数:-123,倒转输出:-321. 给定例子中,存在负数情况,将负数的输入转化成整数统一讨论,同时记录负数标志位,在返回时使用. 优先获取整数的位数,有两种方法:第一种是根据定义出发,循环将输入数字除以10,累加次数.这…

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…

ssh反向通道的可用场景之一:从外网访问内网的主机.所必须的是你需要一个有ssh登录权限的公网主机. 步骤如下(将内网主机称作A,公网ssh主机地址为hostP ): 1.在内网A上执行 :localhost: [user@]hostP #需要身份验证,根据你的情况:无密码.-i 秘钥文件.输入密码 其中remoteListenIp指在hostP上监听22222端口的ip,可以省略.在没有对hostP上的GatewayPorts参数进行设置时不起作用,默认只绑定到本地回环,这可能导致只能在hos…

Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 public class Solution { public int reverse(int x) { boolean isPositive = true; ) { x = -x; isPositive = false; } ; ) { reversedValue = reversedValue * + x % ;…

颠倒数组元素顺序reverse() reverse() 方法用于颠倒数组中元素的顺序. 语法: arrayObject.reverse() 注意:该方法会改变原来的数组,而不会创建新的数组. 定义数组myarr并赋值,然后颠倒其元素的顺序: <script type="text/javascript"> var myarr = new Array(3) myarr[0] = "1" myarr[1] = "2" myarr[2] =…

今天做了下LeetCode上面字符串倒序的题目,突然想Python中字符串倒序都有哪些方法,于是网上查了下,居然有这么多种方法: 个人觉得,第二种方法是最容易想到的,因为List中的reverse方法比较常用,做LeetCode题目7. Reverse Integer也用了这种方法,程序耗时65ms #字符串的反转 #用到for循环的步长参数,从大到小循环,到0为止 def reverse1 (s): rt = '' for i in range(len(s)-1, -1, -1): rt +=…

------------------------------- Java也可以实现一行代码反转字符串哦 AC代码如下: public class Solution { public String reverseString(String s) { return new StringBuffer(s).reverse().toString(); } } 题目来源: https://leetcode.com/problems/reverse-string/…

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 condition:1 ≤ m ≤ n ≤ lengt…