留坑(p.339) 已填(膜汪) 每条直线至少经过两个点,我们不妨在经过的所有点中的第二个点统计它 设f[i][j]表示i * j的答案,那么显然可以用f[i][j] = f[i - 1][j] + f[i][j - 1] - f[i - 1][j - 1] + 以(i, j)这个点为第二个经过的点的直线 这样的直线的数量与(1, 1) ~ (i - 1, j - 1)中与(i, j)横纵坐标差与(i, j)互质的点的数量有关(还要再减掉一写) 而这个数量等于(1, 1) ~ (i - 1, j…

总时间限制: 1000ms 内存限制: 65536kB描述The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware of this problem. They're planning to build some h…

Highways Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 23421   Accepted: 10826 Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Fl…

Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware of this problem. They're planning to build some highways so that i…

点击打开链接 Highways Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 19004   Accepted: 8815 Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia.…

题目连接 http://poj.org/problem?id=2485 Highways Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware of this problem. They…

Highways Time Limit:1000MS     Memory Limit:10000KB     64bit IO Format:%I64d & %I64u Submit Status Practice POJ 1751 Appoint description:  System Crawler  (2015-06-02) Description The island nation of Flatopia is perfectly flat. Unfortunately, Flato…

Highways 题目链接: http://acm.hust.edu.cn/vjudge/contest/124434#problem/G Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has a very poor system of public highways. The Flatopian government is aware of this problem an…

题意: 给出一个n行m列的点阵,求共有多少条非水平非竖直线至少经过其中两点. 分析: 首先说紫书上的思路,编程较简单且容易理解.由于对称性,所以只统计“\”这种线型的,最后乘2即是答案. 枚举斜线包围盒的大小,如果盒子的长宽ab互质,则是可以的.这种盒子共有(m-a)(n-b)个,但要减去其中重复的.如果有一个长宽为2a和2b的大盒子,则计数右下角的小盒子的同时,左上角的小盒子会重复,所以要减去重复的盒子的个数c = max(0, m-2a) * max(0, n-2b) 最后gcd(a, b)…

Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has a very poor system of public highways. The Flatopian government is aware of this problem and has already constructed a number of highways connecting some of the…

Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware of this problem. They're planning to build some highways so that i…

HIGH - Highways   In some countries building highways takes a lot of time... Maybe that's because there are many possiblities to construct a network of highways and engineers can't make up their minds which one to choose. Suppose we have a list of ci…

In some countries building highways takes a lot of time... Maybe that's because there are many possiblities to construct a network of highways and engineers can't make up their minds which one to choose. Suppose we have a list of cities that can be c…

Highways Time Limit : 2000/1000ms (Java/Other)   Memory Limit : 131072/65536K (Java/Other) Total Submission(s) : 4   Accepted Submission(s) : 1 Problem Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public…

Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware of this problem. They're planning to build some highways so that i…

Highways Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 21628   Accepted: 9970 Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Fla…

题目连接:uva 1393 - Highways 题目大意:给定一个m∗n的矩阵,将矩阵上的点两两相连,问有多少条直线至少经过两点. 解题思路:头一次做这样的题目,卡了一晚上. dp[i][j]即为i∗j的矩阵中有多少条红色的线,然后最后答案*2,即水平翻转下蓝色的线.非常easy发现,全部的线都过ij互质的点(即最大公约数为1).然后用容斥原理求出ans. #include <cstdio> #include <cstring> const int N = 305; int n,…

高速公路(SPOJ104 Highways) 一个有n座城市的组成国家,城市1至n编号,当中一些城市之间能够修建快速公路.如今,须要有选择的修建一些快速公路.从而组成一个交通网络.你的任务是计算有多少种方案,使得随意两座城市之间恰好仅仅有一条路径? 数据规模:1≤n≤12. 生成树计数 算法步骤: 1. 构建拉普拉斯矩阵 Matrix[i][j] = degree(i) , i==j -1,i-j有边 0,其它情况 2. 去掉第r行,第r列(r随意) 3. 计算矩阵的行列式 #include <…

Highways Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 23070   Accepted: 6760   Special Judge Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has a very poor system of public highways. The Flatopian…

http://poj.org/problem?id=2485 Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware of this problem. They're planning t…

链接: http://poj.org/problem?id=1751 Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 11507   Accepted: 3279   Special Judge Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has a very poor system of publ…

1090. Highways Constraints Time Limit: 1 secs, Memory Limit: 32 MB Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Flatopian government is aware…

题目链接 Description The islandnation of Flatopia is perfectly flat. Unfortunately, Flatopia has no publichighways. So the traffic is difficult in Flatopia. The Flatopian government isaware of this problem. They're planning to build some highways so that…

Highways Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 14819   Accepted: 4278   Special Judge Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has a very poor system of public highways. The Flatopian…

Highways Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 23033   Accepted: 10612 Description The island nation of Flatopia is perfectly flat. Unfortunately, Flatopia has no public highways. So the traffic is difficult in Flatopia. The Fl…

SPOJ104 Highways Description In some countries building highways takes a lot of time- Maybe that's because there are many possiblities to construct a network of highways and engineers can't make up their minds which one to choose. Suppose we have a l…

[SPOJ]Highways(矩阵树定理) 题面 Vjudge 洛谷 题解 矩阵树定理模板题 无向图的矩阵树定理: 对于一条边\((u,v)\),给邻接矩阵上\(G[u][v],G[v][u]\)加一 对于一条边\((u,v)\),给度数矩阵上\(D[u][u],D[v][v]\)加一 定义霍尔基夫矩阵\(C=D-G\) 将基尔霍夫矩阵去除任意一行和任意一列之后, 得到一个\((n-1)*(n-1)\)的行列式\(C\) 求解这个行列式的值,最后的\(|det(C)|\)就是结果 #includ…

Highways 题目链接:https://vjudge.net/problem/SPOJ-HIGH Description: In some countries building highways takes a lot of time... Maybe that's because there are many possiblities to construct a network of highways and engineers can't make up their minds whi…

HIGH - Highways http://www.spoj.com/problems/HIGH/ In some countries building highways takes a lot of time... Maybe that's because there are many possiblities to construct a network of highways and engineers can't make up their minds which one to cho…

https://vjudge.net/problem/UVA-1393 题意: a*b的点阵中能画多少条非水平非竖直的直线 方向‘/’ 和 方向 ‘\’ 对称 枚举直线所在矩形的i*j 直线可能重复的情况: 1.与矩形内部矩形的直线重复 2.与它左上角的直线连接成一条 如果gcd(i,j)>1, 那么这条直线与gcd(i,j)=1的直线是重复的 所以只枚举互质的i,j 以左上角坐标为(0,0), 这个矩形的左上角为(x,y), 它合法的条件是 x+i<a,y+j<b,一共有(a-i)*(…