上次周赛碰到这个题目,居然都没思路,真是不应该啊,起码也应该想到枚举法. 因为题目只允许每一row进行reverse操作,而每两列可以进行交换操作,所以首先把row的变化固定下来,即枚举第一列与第1-m列进行交换,之后逐个检查每一行第一列的状态 与 终态是否一致,不一致的话则该行就一定要进行reverse操作了,这样下来,每次枚举就把row的reverse变化给固定下来,接下来只要枚举 接下来的2-m行互相的列变换即可,只需一个嵌套循环即可,总的循环也只是三重 而n和m仅有100,规模承担的起…

HDU 4920 Matrix multiplication 题目链接 题意:给定两个矩阵,求这两个矩阵相乘mod 3 思路:没什么好的想法,就把0的位置不考虑.结果就过了.然后看了官方题解,上面是用了bitset这个东西,能够用来存大的二进制数,那么对于行列相乘.事实上就几种情况,遇到0都是0了,1 1得1,2 1,1 2得2,2 2得1.所以仅仅要存下行列1和2存不存在分别表示的二进制数.然后取且bitcount一下的个数,就能够计算出对应的数值了 代码: 暴力: #include <cst…

其实和昨天写的那道水题是一样的,注意爆LL $1<=n,k<=1e9$,$\sum\limits_{i=1}^{n}(k \mod i) = nk - \sum\limits_{i=1}^{min(n,k)}\lfloor\frac{k}{i}\rfloor i$ /** @Date : 2017-09-21 19:55:31 * @FileName: HDU 2620 分块底数优化 暴力.cpp * @Platform: Windows * @Author : Lweleth (SoungE…

HDU 2686 Matrix 题目链接 3376 Matrix Again 题目链接 题意:这两题是一样的,仅仅是数据范围不一样,都是一个矩阵,从左上角走到右下角在从右下角走到左上角能得到最大价值 思路:拆点.建图,然后跑费用流就可以,只是HDU3376这题,极限情况是300W条边,然后卡时间过了2333 代码: #include <cstdio> #include <cstring> #include <vector> #include <queue>…

Lara Croft, the fiercely independent daughter of a missing adventurer, must push herself beyond her limits when she discovers the island where her father disappeared. In this mysterious island, Lara finds a tomb with a very heavy door. To open the do…

又一发吐血ac,,,再次明白了用函数(代码重用)和思路清晰的重要性. 11779687 2014-10-02 20:57:53 Accepted 4770 0MS 496K 2976 B G++ czy Lights Against Dudely Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1360    Accepted Subm…

题目 这是一道可以暴力枚举的水题. //以下两个都可以ac,其实差不多一样,呵呵 //1: //4 wei shu #include<stdio.h> struct tt { ],b[],c[]; }e[]; int main() { ],mark[],yi,flag,a1,a2,a3,a4; while(scanf("%d",&n),n) { ;i<n;i++) { scanf("%s%s%s",e[i].a,e[i].b,e[i].c)…

Crazy Tank Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 4562    Accepted Submission(s): 902 Problem Description Crazy Tank was a famous game about ten years ago. Every child liked it. Time f…

USACO ORZ Time Limit: 5000/1500 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3809    Accepted Submission(s): 1264 Problem Description Like everyone, cows enjoy variety. Their current fancy is new shapes for pastu…

HDU 4930 Fighting the Landlords 题目链接 题意:就是题中那几种牌型.假设先手能一步走完.或者一步让后手无法管上,就赢 思路:先枚举出两个人全部可能的牌型的最大值.然后再去推断就可以 代码: #include <cstdio> #include <cstring> #include <algorithm> using namespace std; struct Player { int rank[15]; } p1, p2; int t,…

题意:给定 13 张麻将牌,问你是不是“听”牌,如果是输出“听”哪张. 析:这个题,很明显的暴力,就是在原来的基础上再放上一张牌,看看是不是能胡,想法很简单,也比较好实现,结果就是TLE,一直TLE,这不科学啊... 好不容易写出来的,竟然TLE...心痛.就是先确定一个将牌,然后再对刻子和顺子进行分析,其实是要剪枝的,就是在如果有1张或者两张牌,而你又不能构成刻子的时候,就要返回false,因为这就已经没解了. 这一个剪枝,就AC了. 代码如下: #pragma comment(linker,…

题意:... 析:我们可以知道,a1+a2=b1,那么我们可以枚举a1,那么a2就有了,并且a1+a3=b2,所以a3就有了,我们再从把里面的剩下的数两两相加,并从b数组中去掉, 那么剩下的最小的就是a4,然后依次可以求出a5,a6....由于a最大才是5000,并且保证有唯一解,那么找到一个就直接退出. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #incl…

Problem Description Let L denote the number of 1s in integer D’s binary representation. Given two integers S1 and S2, we call D a WYH number if S1≤L≤S2. With a given D, we would like to find the next WYH number Y, which is JUST larger than D. In othe…

题目链接:pid=4462">传送门 题意:一个n*n的区域,有m个位置是能够放稻草人的.其余都是玉米.对于每一个位置(x,y)所放稻草人都有个作用范围ri, 即abs(x-i)+abs(y-j)<=r,(i,j)为作用范围内.问至少要在几个位置上放稻草人,才干覆盖全部的玉米,若不可能则输出-1. 有一个trick,就是放稻草人的位置不用被覆盖 eg: input: 2 4 1 1 1 2 2 1 2 2 0 0 0 0 output: 0 0 代码例如以下: #include &l…

YJC counts stars Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5277 Description YJC是个老火车小司机.一个晚上,他仰望天空,星辰璀璨,他突然觉得,天空就像一个平面,而每一个星辰,就是平面中的一个点.他把这些点编号为1到n.这些点满足任意三点不共线.他把一些点用线段连起来了,但是任意两条线段不会在端点以外相交.如果一个点的集合中任意两个…

abs 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5778 Description Given a number x, ask positive integer y≥2, that satisfy the following conditions: The absolute value of y - x is minimal To prime factors decomposition of Y, every element factor a…

http://acm.hdu.edu.cn/showproblem.php?pid=5442 题意:给出一串字符串,它是循环的,现在要选定一个起点,使得该字符串字典序最大(顺时针和逆时针均可),如果有多个字典序相同的,则输出下标最小的,如果下标也是相同的,则输出顺时针方向的. 思路:用了三种方法: ①最简单的,暴力枚举所有情况,需要优化一下,先处理出字符串中字典序最大的单词,然后接下来的起点肯定是这个单词,否则就可以跳过这个起点. #include<iostream> #include<…

http://acm.hdu.edu.cn/showproblem.php?pid=5510 想了很久队友叫我用ufs + kmp暴力过去了. fa[x] = y表示x是y的子串,所以只有fa[x] == x才需要kmp一次. 那么这样的话,如果全部都不互为子串的话,复杂度还是爆咋的. #include <iostream> #include <cstdio> #include <cstring> #include <cmath> #include <…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2069 Problem Description Suppose there are 5 types of coins: 50-cent, 25-cent, 10-cent, 5-cent, and 1-cent. We want to make changes with these coins for a given amount of money.For example, if we have 11…

Matrix Swapping II Time Limit: 9000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1430    Accepted Submission(s): 950 Problem Description Given an N * M matrix with each entry equal to 0 or 1. We can find som…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4920 解题报告:求两个800*800的矩阵的乘法. 参考这篇论文:http://wenku.baidu.com/link?url=261XeEzH-AZkFGPiN63t1nnojoQF50yiuMoviHroGjVXjjRlxFcvWLcws0jgQcmZo4oA9BJcjnPxVreWRu-XXa9zb6r5gUUTxmBXn_qWSsu&qq-pf-to=pcqq.group 我看过了,只是简…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2686 Yifenfei very like play a number game in the n*n Matrix. A positive integer number is put in each area of the Matrix.Every time yifenfei should to do is that choose a detour which frome the top left…

Teacher Bo 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5762 Description Teacher BoBo is a geography teacher in the school.One day in his class,he marked N points in the map,the i-th point is at (Xi,Yi).He wonders,whether there is a tetrad (A,B,C,…

matrix Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5569 Description Given a matrix with n rows and m columns ( n+m is an odd number ), at first , you begin with the number at top-left corner (1,1) and you wa…

http://acm.hdu.edu.cn/showproblem.php?pid=4712 Hamming Distance Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 797    Accepted Submission(s): 284 Problem Description (From wikipedia) For binary…

题目链接:hdu 4876 ZCC loves cards 题目大意:给出n,k,l,表示有n张牌,每张牌有值.选取当中k张排列成圈,然后在该圈上进行游戏,每次选取m(1≤m≤k)张连续的牌,取牌上值的亦或和.要求找到一个圈,使得L~R之间的数都能够得到,输出R.假设R < L输出0. 解题思路:暴力,首先预处理出来每种选取的亦或值,然后在该基础上从能够组成L的状态中挑选一个,L+1的状态中挑取一个,知道说总的挑取出全部状态中选中的牌的个数大于K为值,然后用全排序去查找最大的R. #includ…

题目链接 Problem Description We know that some positive integer x can be expressed as x=A^2+B^2(A,B are integers). Take x=10 for example, 10=(-3)^2+1^2.We define R(N) (N is positive) to be the total number of variable presentation of N. So R(1)=4, which…

Fliptile Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 14297   Accepted: 5257 Description Farmer John knows that an intellectually satisfied cow is a happy cow who will give more milk. He has arranged a brainy activity for cows in whic…

各种TEL,233啊.没想到是处理掉0的情况就能够过啊.一直以为会有极端数据.没想到居然是这种啊..在网上看到了一个AC的奇妙的代码,经典的矩阵乘法,仅仅只是把最内层的枚举,移到外面就过了啊...有点不理解啊,复杂度不是一样的吗.. Matrix multiplication Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 640 …

DES:从23个队员中选出4—4—2—1共4种11人来组成比赛队伍.给出每个人对每个职位的能力值.给出m组人在一起时会产生的附加效果.问你整场比赛人员的能力和最高是多少. 用深搜暴力枚举每种类型的人选择情况.感觉是这个深搜写的很机智. 在vector中存结构体就会很慢.TLE.直接存序号就AC了.以后还是尽量少用结构体吧. #include<stdio.h> #include<string.h> #include<map> #include<vector>…