这个题目套公式 2^(n-1)-1,再来个快速幂基本上就可以AC了 写这个题目的: 公式容易推到错: 容易写成 2^n-1/2...这样写出来结果也不错  但是一直哇 AC: #include<iostream> #include<cstdio> #include<cstring> #define N 1000000007 using namespace std; typedef long long ll; int pow(ll x,ll y) { ll res=; w…

http://acm.hdu.edu.cn/showproblem.php?pid=5363 Key Set Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 549    Accepted Submission(s): 338 Problem Description soda has a set S with n integers {…

题 Description soda has a set $S$ with $n$ integers $\{1, 2, \dots, n\}$. A set is called key set if the sum of integers in the set is an even number. He wants to know how many nonempty subsets of $S$ are key set.   Input There are multiple test cases…

题 Description soda has a set $S$ with $n$ integers $\{1, 2, \dots, n\}$. A set is called key set if the sum of integers in the set is an even number. He wants to know how many nonempty subsets of $S$ are key set.   Input There are multiple test cases…

Time Limit: 2000/1000 MS (Java/Others)   Memory Limit: 131072/131072 K (Java/Others) Problem Description soda has a set S with n integers {1,2,…,n}. A set is called key set if the sum of integers in the set is an even number. He wants to know how man…

2015 HDU 多校联赛 5363 Key Set 题目: http://acm.hdu.edu.cn/showproblem.php? pid=5363 依据前面给出的样例,得出求解公式 fn = 2^(n-1) - 1, 数据量大,实际就是求幂次方. 可用分治法求解.复杂度O(nlogn) // 分治法求高速幂 #include <bits/stdc++.h> using namespace std; typedef unsigned long long ull; const int M…

题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=1885 Key Task Description The Czech Technical University is rather old — you already know that it celebrates 300 years of its existence in 2007. Some of the university buildings are old as well. And the…

题意:矩阵中'#'表示墙,'.'表示通路,要求从起点'*'到达终点'X',途中可能遇到一些门(大写字母),要想经过,必须有对应的钥匙(小写字母).问能否完成,若能,花费的时间是多少. 分析:同hdu 1429,只不过这里用map把四种钥匙标号了,否则爆内存. 错误:判断门的条件用 isupper(ch) 表示,所以终点'X'也在这个范围内. #include<cstdio> #include<cstring> #include<cctype> #include<m…

题目 之前比赛的一个题, 当时是崔老师做的,今天我自己做了一下.... 还要注意用bfs的时候  有时候并不是最先到达的就是答案,比如HDU 3442 这道题是要求最小的消耗血量伤害,但是并不是最先到达目标点的路径 就是最小的伤害,因为每一个点的伤害是 不一样的, 这种情况要用优先队列优化, 对伤害优化. 题意:*开始, X出口, b, y, r, g 代表钥匙,分别可以开B, Y, R, G颜色的门, 钥匙可以多次使用.问最短的步骤. 思路:vis[][][]数组开三维,第三维记录状态 是否拿…

题目链接 题意 : 出口不止一个,一共有四种颜色不同的门由大写字母表示,而钥匙则是对应的小写字母,当你走到门前边的位置时,如果你已经走过相应的钥匙的位置这个门就可以走,只要获得一把钥匙就可以开所有同颜色的门.问你能不能走出来. 思路 : 这个题比赛的时候完全没有思路,想了好久脑子都疼了也没想出来.原来是一个三维的BFS,因为要拿钥匙的缘故可能有些地方要来回走,所以不能像以前标记二维一样只要走过的点就不能走了,这里用三维来标记,你要是走过这个地方并且钥匙数都是一样的,那就不用再走了,因为那代表你又…

HDU 3313 Key Vertex 题目链接 题意:一个有向无环图.求s,t之间的割点 思路:先spfa找一条最短路出来,假设不存在.就n个都是割点. 然后每次从s进行dfs,找到能经过最短路上的最远点.然后这个点就是割点.然后下次在以这个为起点dfs,不断迭代直到找到t为止 代码: #include <cstdio> #include <cstring> #include <vector> #include <queue> #include <a…

传送门: http://acm.hdu.edu.cn/showproblem.php?pid=1885 Key Task Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2654    Accepted Submission(s): 1143 Problem Description The Czech Technical Universi…

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 487 Accepted Submission(s): 157 Problem Description Many people think that Tetris was invented by two Russian programmers. But that is not the whole…

题意:给定一个n*m的矩阵,里面有门,有钥匙,有出口,问你逃出去的最短路径是多少. 析:这很明显是一个BFS,但是,里面又有其他的东西,所以我们考虑状态压缩,定义三维BFS,最后一维表示拿到钥匙的状态,然后再BFS,就简单了. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib&…

Problem Description The Czech Technical University years of its existence . Some of the university buildings are old as well. And the navigation in old buildings can sometimes be a little bit tricky, because of strange long corridors that fork and jo…

点击打开链接 Key Task Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1176    Accepted Submission(s): 462 Problem Description The Czech Technical University is rather old - you already know that it c…

http://acm.hdu.edu.cn/showproblem.php?pid=1885 再贴一个链接http://blog.csdn.net/u013081425/article/details/21756237 #include <stdio.h> #include <string.h> #include <algorithm> #include <stack> #include <vector> #include <queue&g…

Key Vertex Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 1347    Accepted Submission(s): 305 Problem Description You need walking from vertex S to vertex T in a graph. If you remove one vert…

Description soda has a set S with n integers {1,2,…,n}. A set is called key set if the sum of integers in the set is an even number. He wants to know how many nonempty subsets of S are key set.   Input There are multiple test cases. The first line of…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5363 Problem Description soda has a set S with n integers {1,2,…,n}. A set is called key set if the sum of integers in the set is an even number. He wants to know how many nonempty subsets of S are key s…

http://acm.hdu.edu.cn/showproblem.php?pid=4771 给一个地图,@是起点,给一些物品坐标,问取完所有物品的最小步数,不能取完输出-1 物品数最多只有四个,状态压缩一下bfs即可 #include <iostream> #include <cstdio> #include <algorithm> #include <queue> #include <cstring> using namespace std;…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4006 题目大意: 第一行 输入 n k,后有 n 行,对于每一行有两种状态 ,①“I x” : 插入 x ② “Q” : 输出当前 第 K大的数 解题思路: 利用优先队列保证插入新数据后的队列是有序的. 重点:保证 k 个数的队列就行.加一个标志 flag_k; I: 如果 flag_k<k,则将新输入的数放入队列中. 否则判断第k个数是否小于新输入的数,如果小于,则队头出队,新输入的入队:保证队列…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1873 题目大意: 三个医生看病,病人排队看病,病人有优先级,优先级高的提前看病,同样的优先级按先后.IN A B : A医生有B病人.OUT  A:A医生看完病人.输入看完病的病人是第几个来的.如果当前的医生没有看病人,输出“EMPYT”. 解题思路: 三个医生队列(优先队列:可以自动排序,解决了优先级问题),定义一个病人结构体,记录病人的顺序 key 和优先级priority,如果当前病人看1号医…

题目: http://acm.hdu.edu.cn/showproblem.php?pid=2222 AC自动机模板题 我现在对AC自动机的理解还一般,就贴一下我参考学习的两篇博客的链接: http://blog.csdn.net/niushuai666/article/details/7002823 http://www.cppblog.com/menjitianya/archive/2014/07/10/207604.html #include<stdio.h> #include<s…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2852 题目大意:操作①:往盒子里放一个数.操作②:从盒子里扔掉一个数.操作③:查询盒子里大于a的第K小数. 解题思路: 由于模型是盒子,而不是序列,所以可以用树状数组的顺序维护+逆序数思想. 对应的树状数组Solution: 放一个数 $Add(val,1)$ 类似维护逆序数的方法,对应位置上计数+1. 注意Add的while范围要写成$while(x<maxn)$ 如果范围不是最大,那么会导致某些…

How to Type Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 6072    Accepted Submission(s): 2729 Problem Description Pirates have finished developing the typing software. He called Cathy to tes…

HDU  2577 Description Pirates have finished developing the typing software. He called Cathy to test his typing software. She is good at thinking. After testing for several days, she finds that if she types a string by some ways, she will type the key…

今天又爆零了,又是又,怎么又是又,爆零爆多了,又也就经常挂嘴边了,看到这句话,你一定很想说一句””,弱菜被骂傻,也很正常啦. 如果你不开心,可以考虑往下看. 翻到E(HDU 4635 Strongly connected)题,这么短的题目,肯定要先看啦.然后D(LightOJ 1229),然后C(ZOJ 2243),然后F(HDU 4711),然后B(CodeForces 385D),然后看A(HDU 3889)好吧,我承认,A题看了一眼就不看了,B题一看是线段什么有点几何的味道就果断放弃,然后…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5101 题目意思:给出 n 个 classes 和 Dudu 的 IQ(为k),每个classes 都有相应的人,每个人又有相应的IQ.现在要求从这些classes挑选两个人,满足IQ之和 > k,不过要满足这两个人不能来自同一个class的. 解题思路不难想出,直接所有人两两之和 > k - 同一个class 两两之和 > k  就是答案了. 不过很容易超时!!!! 用二分就可以过了.二分有…

A - Hero Time Limit:3000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 4310 Description When playing DotA with god-like rivals and pig-like team members, you have to face an embarrassing situation: All your t…