超级经典的题目,扫描区间,滑动窗口 对这题目的最大感受就是,单独看这个题目,其实不难,但是很多我感觉挺难或者没做出来的题目,都是由这些若干个经典的算法组合而成的 滑动窗口便是一个典型的例子!!!!遇到过好几道用到滑动窗口的题目 而本题则赤裸裸的滑动窗口 题意: 输入一个长度为n的序列A,找一个尽可能长的子序列使他们之间无重复元素 思路: 第一步,自己暴力模拟 第二步,找规律,尝试着状态转移 第三步,修正,实现 首先不能重复,那么我们先假设区间[l, r] 无重复元素,那么加入一个元素a[r+1]…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 39324   Accepted: 10298 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true.…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 27312   Accepted: 7213 题目链接:http://poj.org/problem?id=3349 Description You may have heard that no two snowflakes are alike. Your task is to write a program to dete…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 30529   Accepted: 8033 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Y…

Snowflake Snow Snowflakes Time Limit: 4000MS Memory Limit: 65536K Total Submissions: 27598 Accepted: 7312 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Your…

http://poj.org/problem?id=3349 Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 37609   Accepted: 9878 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine…

Snowflake Snow Snowflakes Time Limit: 4000MS Memory Limit: 65536K Total Submissions: 34762 Accepted: 9126 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Your…

Snowflake Snow Snowflakes Time Limit: 4000MS Memory Limit: 65536K Total Submissions: 37615 Accepted: 9882 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Your…

//突然发现好弱,好多基础的算法竟然都不会,哈希这种经典的算法,我貌似基本没怎么做过相关的题0.0 POJ2002 题意:给n个点,问有多少组四个点能组成正方形. 题解:枚举两个点,通过公式算出另外两个点,然后通过哈希查找另外两个点存不存在. 公式是抄网上的,哈希直接用了vector存的,反正时限3500ms 点的哈希就是(x^2+y^2)%MOD AC代码: /************************************** Memory: 924 KB Time: 969 MS…

http://poj.org/problem?id=3349 题意 :分别给你n片雪花的六个角的长度,让你比较一下这n个雪花有没有相同的. 思路:一开始以为把每一个雪花的六个角的长度sort一下,然后再跟别的比,可实际上不是这样的,两个雪花相同的时候,角的顺序是固定的,可以是逆时针的也可以是顺时针的,因为雪花可以转动嘛,例如213456 和216543就是不一样的,这个题本身分类就是哈希,但是看到讨论里有人用暴力过的,,,我很是佩服,我压根就没往那个方面想,也许分类是哈希,我就认定哈希了吧,思维…

考察hash表: 每一个雪花都有各自的6个arm值,如果两个雪花从相同或者不同位置开始顺时针数或者逆时针数可以匹配上,那么这两个雪花就是相等的. 我们采用hash的方法,这样每次查询用时为O(1),总用时为O(n). hash的本质是把值映射到地址或者下标,如果不同的key值对应到相同的indice上的话,就需要进行chaining处理,吧indice指向一个链表,链表的每一个节点存储共享同一indice的不同key值. 因此问题的核心变成:吧相等的雪花映射到相同的indice上.这里雪花是一个…

题目链接: http://poj.org/problem?id=3349 #include <stdio.h> #include <string.h> #include <iostream> using namespace std; ; struct Snow { ]; }snow[]; struct HashTable { struct Snow *data; struct HashTable *next; HashTable() { next = NULL; } }…

Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 27277   Accepted: 7197 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Your program will read info…

题目链接. 分析: 哈希竟然能这么用.检查两片雪花是否相同不难,但如果是直接暴力,定会超时.所以要求哈希值相同时再检查. AC代码: #include <iostream> #include <cstdio> #include <cstdlib> #include <string> #include <algorithm> #include <vector> #include <map> #include <cstr…

今天学的hash.说实话还没怎么搞懂,明天有时间把知识点总结写了,今天就小小的写个结题报告吧! 题意: 在n (n<100000)个雪花中判断是否存在两片完全相同的雪花,每片雪花有6个角,每个角的长度限制为1000000 两片雪花相等的条件: 雪花6个角的长度按顺序相等(这个顺序即可以是顺时针的也可以是逆时针的) 解题思路: hash:连加求余法 求key 值,链地址法解决冲突,连加求余法 求key 值挺简单,关于链地址法解决冲突可以通过c++中,vector容器可以较为方便的实现. 下面先介绍…

链接:Snowflake Snow Snowflakes 判断所有的雪花里面有没有相同的 每次把雪花每个角的值进行相加和相乘 之后hash #include<iostream> #include<algorithm> #include<cstring> #include<stdio.h> using namespace std; typedef long long LL; ; ,p=; ],head[maxn],nex[maxn]; int he(int *…

Emily the entrepreneur has a cool business idea: packaging and selling snowflakes. She has devised a machine that captures snowflakes as they fall, and serializes them into a stream of snowflakes that flow, one by one, into a package. Once the packag…

题意:一个雪花有六个角  给出N个雪花 判断有没有相同的(可以随意旋转) 参考:https://blog.csdn.net/alongela/article/details/8245005 注意:参考的博客的写法有问题  不知道POJ为什么没有卡掉 例如 数据         1 1 1 1 1 1 1 如果用这个博客的写法 等于自己和自己比了 输出的是yes 只要稍微改一下  改成比完之后插入key就能解决了 疑问:  manx=1000000+10会T 改成1200000+10才能过不知道为…

吼哇! 关于开散列哈希: 哈希就是把xxx对应到一个数字的东西,可以理解成一个map<xxx, int>(是不是比喻反了) 我们要设计一个函数,这个函数要确保同一个东西能得到相同的函数值(废话) 然后在函数值域上开邻接表即可. 本人第一次写hash,还不是经典字符串hash而是雪花雪雪花(......) 那么接下来欣赏丑陋不堪的hash吧! (poj上C++过不了,RE,G++就过了,有剧毒) #include <cstdio> , P = ; ]; struct Snowflak…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 48646   Accepted: 12703 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true.…

You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Your program will read information about a collection of snowflakes, and search for a pair that may be identical. Each snow…

这是一道可以练习哈希表的模板题.关于哈希表的操作均有涉及. 哈希函数的选取是这道题的关键.这道题的关键字是一个长度为6的序列,并且序列与开始顺序.时钟顺序均无关. 因此,采用哈希函数\(H[x]=\Sigma_{i=0}^5a[i]+\prod_{i=0}^5a[i]\),即:用加和乘的相加来进一步保证散列性. 另外,不能采用带"权值"的哈希函数,因为无序性. 另一个小知识点是顺时针和逆时针的操作,顺时针加 k 取模即可,逆时针正常来说减 k 取模即可,不过可能出现负数,因此再加上6.…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 43504   Accepted: 11411 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true.…

http://poj.org/problem?id=3349 题意: 给出n片雪花留个角的长度,要求判断是否有一样的雪花. 思路: Hash表的应用. 首先将每个雪花所有角的总长计算出来,如果两片雪花相同的话那么总长也是相同的,然后加入vector容器当中,最后遍历vector数组,如果某个总长有大于1的雪花数,则有可能存在相同的雪花,此时需要比较这些雪花. #include <iostream> #include <stdio.h> #include <vector>…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 30512   Accepted: 8024 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true. Y…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 49991   Accepted: 13040 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true.…

首先声明代码并没有AC,内存超了 但我对此无能为力,有没有哪位大神好心教一下怎么写 哈希,然后比较花瓣数组,这些应该都没问题才对..唉.. 贴MLE代码 import java.util.*; public class POJ3349 { static int N = 1200007; public static class HashNode{ int[] num=null; HashNode next = null; } // hashlist[i]存储hash值为i的链表 static Ha…

Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 48624   Accepted: 12697 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is really true.…

相应POJ题目:点击打开链接 Snowflake Snow Snowflakes Time Limit: 4000MS   Memory Limit: 65536K Total Submissions: 33595   Accepted: 8811 Description You may have heard that no two snowflakes are alike. Your task is to write a program to determine whether this is…

判断n朵雪花中,是否有完全一样的雪花.简单的hash,将雪花的六个边的权值加起来,记为sum,将sum相等的雪花归为一类,再在这里面根据题意找完全相同的,判断顺时针或者逆时针的所有角是否一模一样. #include<vector> #include<stdio.h> ; std::vector<]; ][]; int isSame(int s1,int s2){ ;i<;i++){ ; ,k=i;j<;j++,k=(k+)%){ if(arm[s1][j]!=ar…