题意:除了所给的一些点外,问能不能用1*2的矩形覆盖所有的点,矩形间不能重叠. 思路:简单二分匹配,,,,,,, #include<stdio.h> #include<string.h> const int N=1200; int match[N],link[N],map[35][35],n,m; int dir[4][2]={0,1,0,-1,1,0,-1,0}; int find(int u) { int i,v,x,y,X,Y; x=u/m;y=u%m; for(i=0;i&…
The Perfect Stall Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 23313 Accepted: 10383 Description Farmer John completed his new barn just last week, complete with all the latest milking technology. Unfortunately, due to engineering p…
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1281 Problem Description 小希和Gardon在玩一个游戏:对一个N*M的棋盘,在格子里放尽量多的一些国际象棋里面的“车”,并且使得他们不能互相攻击,这当然很简单,但是Gardon限制了只有某些格子才可以放,小希还是很轻松的解决了这个问题(见下图)注意不能放车的地方不影响车的互相攻击. 所以现在Gardon想让小希来解决一个更难的问题,在保证尽量多的“车”的前提下,棋盘里有些格…
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1281 棋盘游戏 Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 2905 Accepted Submission(s): 1702 Problem Description 小希和Gardon在玩一个游戏:对一个N*M的棋盘,在格子里放尽…
二分匹配:二分图的一些性质 二分图又称作二部图,是图论中的一种特殊模型. 设G=(V,E)是一个无向图,如果顶点V可分割为两个互不相交的子集(A,B),并且图中的每条边(i,j)所关联的两个顶点i和j分别属于这两个不同的顶点集(i in A,j in B),则称图G为一个二分图. 1.一个二分图中的最大匹配数等于这个图中的最小点覆盖数 König定理是一个二分图中很重要的定理,它的意思是,一个二分图中的最大匹配数等于这个图中的最小点覆盖数.如果你还不知道什么是最小点覆盖,我也在这里说一下:假如选…
题目:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2361 来源:http://acm.hust.edu.cn/vjudge/contest/view.action?cid=26760#problem/B Beloved Sons Time Limit: 2 Seconds Memory Limit: 65536 KB Special Judge Once upon a time there liv…
The Perfect Stall Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 24081 Accepted: 10695 Description Farmer John completed his new barn just last week, complete with all the latest milking technology. Unfortunately, due to engineering p…
Description Professor Clumsey is going to give an important talk this afternoon. Unfortunately, he is not a very tidy person and has put all his transparencies on one big heap. Before giving the talk, he has to sort the slides. Being a kind of minima…
The Perfect Stall Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 16396 Accepted: 7502 Description Farmer John completed his new barn just last week, complete with all the latest milking technology. Unfortunately, due to engineering pr…
[题意] 给定有向图 G=(V,E).设 P 是 G 的一个简单路(顶点不相交) 的集合.如果 V 中每个顶点恰好在 P 的一条路上,则称 P 是 G 的一个路径覆盖. P 中路径可以从 V 的任何一个顶点开始, 长度也是任意的, 特别地, 可以为 0. G 的最小路径覆盖是 G 的所含路径条数最少的路径覆盖.设计一个有效算法求一个有向无环图 G 的最小路径覆盖. 输入文件示例 input.txt11 121 21 31 42 53 64 75 86 97 108 119 1110 11输出文件…
奔小康赚大钱 Time Limit: 1000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1836 Accepted Submission(s): 798 Problem Description 传说在遥远的地方有一个非常富裕的村落,有一天,村长决定进行制度改革:重新分配房子.这可是一件大事,关系到人民的住房问题啊.村里共有n间房间,刚好有n家老百姓,考虑到每…
COURSES Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 18993 Accepted: 7486 Description Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is poss…
Cyclic Tour Time Limit: 1000/1000 MS (Java/Others) Memory Limit: 32768/65535 K (Java/Others)Total Submission(s): 1197 Accepted Submission(s): 626 Problem Description There are N cities in our country, and M one-way roads connecting them. Now Li…
The dog task Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 2559 Accepted: 1038 Special Judge Description Hunter Bob often walks with his dog Ralph. Bob walks with a constant speed and his route is a polygonal line (possibly self-in…
Asteroids Time Limit: 1000MS Memory Limit: 65536K Description Bessie wants to navigate her spaceship through a dangerous asteroid field in the shape of an N x N grid (1 <= N <= 500). The grid contains K asteroids (1 <= K <= 10,000), wh…
