There are N integers in an array A. All but one integer occur in pairs. Your task is to find out the number that occurs only once. Input Format The first line of the input contains an integer N indicating number of integers. The next line contains N …

[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…

题目链接:Running Time of Quicksort Challenge In practice, how much faster is Quicksort (in-place) than Insertion Sort? Compare the running time of the two algorithms by counting how many swaps or shifts each one takes to sort an array, and output the dif…

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…

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[]…

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…

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…

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…

https://www.hackerrank.com/challenges/how-many-substrings/problem 题解 似乎是被毒瘤澜澜放弃做T3的一道题(因为ASDFZ有很多人做过,当然,他换了一道更毒瘤的--) 仓鼠在最后一天的时候提了一嘴然后我发现依旧菜菜的不会--(因为太菜模拟天天被吊打) 仓鼠好神仙啊%%%(烤熟了味道怎么样啊) 这道题三个数据结构结合在一起使用,但是感觉却没有那么码农,就是直接把板子套一套(当然板子不熟另当别论),用namespace的话可以降低编码…

Integer to Roman Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 逐区间做处理. 解法一:非递归 class Solution { public: string intToRoman(int num) { string ret; //M<-->1000 ) { ret += 'M'; num -= ; } //t…

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…

题目链接:Median 做了整整一天T_T 尝试了各种方法: 首先看了解答,可以用multiset,但是发现java不支持: 然后想起来用堆,这个基本思想其实很巧妙的,就是维护一个最大堆和最小堆,最大堆存放前半部分较小的元素,最小堆存放后半部分较大的元素,并且最大堆的所有元素小于最小堆的所有元素:保持最大堆最多比最小堆多一个元素.每次插入元素的时候都先插入到最大堆,如果发现最大堆比最小堆多了两个个,那么就从最大堆里面拿出最大的放到最小堆里面:如果发现最大堆里面新插入的元素破坏了最大堆所有元素小于…

题目链接:Coin on the Table 一开始想用DFS做的,做了好久都超时. 看了题解才明白要用动态规划. 设置一个三维数组dp,其中dp[i][j][k]表示在时间k到达(i,j)所需要做的最小改动,那么递推式如下: 图片来源:Editorial,其中当从周围的格子可以直接移动到(i,j)时,delta=0:否则,需要改变周围格子的方向符号,delta=1. 即k-1时刻在(i,.j)周围的四个格子,然后在k时刻移动到(i,j).并且,看这四个格子中的方向符号是否直接可以完成这次移动,…

题目链接:Pairs 完全就是Two Sum问题的变形!Two Sum问题是要求数组中和正好等于K的两个数,这个是求数组中两个数的差正好等于K的两个数.总结其实就是“骑驴找马”的问题:即当前遍历ar[i],那么只要看数组中是否存在ar[i]+K或者ar[i]-K就可以了,还是用HashMap在O(1)的时间完成这个操作. 题目有一点没说清楚的就是元素是否有重复,从Editorial来看似乎是没有重复,不过我还是用map的value记录了数出现的频率来处理了重复. 代码如下: import jav…

题目链接:Cut the tree 题解:题目要求求一条边,去掉这条边后得到的两棵树的节点和差的绝对值最小. 暴力求解会超时. 如果我们可以求出以每个节点为根的子树的节点之和,那么当我们去掉一条边(a,b)的时候,其中的一棵树必是以a或者b为根的子树,那么我们就可以知道生成的两棵树的节点之和了.所以,当我们得到以每个节点为根的子树节点和这个信息后(把这个信息存储在TreeNode的value变量中),通过遍历每个节点(每个节点为根的子树必然为某次cut得到的子树之一,例如下图中,2为根的子树对应…

Sorting is often useful as the first step in many different tasks. The most common task is to make finding things easier, but there are other uses also. Challenge Given a list of unsorted numbers, can you find the numbers that have the smallest absol…

In the Quicksort challenges, you sorted an entire array. Sometimes, you just need specific information about a list of numbers, and doing a full sort would be unnecessary. Can you figure out a way to use your partition code to find the median in an a…

Sunny and Johnny together have M dollars which they intend to use at the ice cream parlour. Among N flavors available, they have to choose two distinct flavors whose cost equals M. Given a list of cost of N flavors, output the indices of two items wh…

题目连接:Sherlock and MiniMax Watson gives Sherlock an array A1,A2...AN. He asks him to find an integer M between P and Q(both inclusive), such that, min {|Ai-M|, 1 ≤ i ≤ N} is maximised. If there are multiple solutions, print the smallest one. Input For…

有n组好朋友在公交车站前排队.第i组有ai个人.还有一辆公交车在路线上行驶.公交车的容量大小为x,即它可以同时运载x个人. 当车站来车时(车总是空载过来),一些组从会队头开始走向公交车. 当然,同一组的朋友不想分开,所以仅当公交车能容纳下整个组的时候,他们才会上车.另外,每个人不想失去自己的位置,即组的顺序不会改变. 问题时如何选择公交车的容量大小x使得它可以运走所有组的人,并且公交车每次从车站出发时没有空位?(在车里的总人数恰好达到x)? 输入格式 第一行只包含一个整数n.第二行包含n个空格分…

QuickSort In the previous challenge, you wrote a partition method to split an array into 2 sub-arrays, one containing smaller elements and one containing larger elements. This means you 'sorted' half the array with respect to the other half. Can you…

In this challenge you need to print the data that accompanies each integer in a list. In addition, if two strings have the same integers, you need to print the strings in their original order. Hence, your sorting algorithm should be stable, i.e. the…

Sherlock and The Beast Sherlock Holmes is getting paranoid about Professor Moriarty, his archenemy. All his efforts to subdue Moriarty have been in vain. These days Sherlock is working on a problem with Dr. Watson. Watson mentioned that the CIA has b…

Animesh has N empty candy jars, numbered from 1 to N, with infinite capacity. He performs M operations. Each operation is described by 3 integers a, b and k. Here, a and b are index of the jars, and k is the number of candies to be added inside each…

给定两个整数:L 和 R ∀ L ≤ A ≤ B ≤ R, 找出 A xor B 的最大值. 输入格式 第一行包含 L 第一行包含 R 数据范围 1 ≤ L ≤ R ≤ 103 输出格式 输出最大的异或和 题解: import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*; public class Solution { /* * Complete t…

Change language : Alex is attending a Halloween party with his girlfriend Silvia. At the party, Silvia spots a giant chocolate bar. If the chocolate can be served as only 1 x 1 sized pieces and Alex can cut the chocolate bar exactly K times, what is…

 Calvin is driving his favorite vehicle on the 101 freeway. He notices that the check engine light of his vehicle is on, and he wants to service it immediately to avoid any risks. Luckily, a service lane runs parallel to the highway. The length of th…