本文版权归ljh2000和博客园共有,欢迎转载,但须保留此声明,并给出原文链接,谢谢合作. 本文作者:ljh2000 作者博客:http://www.cnblogs.com/ljh2000-jump/转载请注明出处,侵权必究,保留最终解释权! 题目链接:SPOJ104 正解:矩阵树定理+高斯消元 解题报告: 写的第一发$Matrix-Tree$定理题QAQ 这道题要求一张无向图的生成树个数,既然是模板题,窝直接上结论辣:构造一个新的矩阵:度数矩阵-邻接矩阵, 对这个新的矩阵去掉第$r$行.第$r…

欲学矩阵树定理必先自宫学习一些行列式的姿势 然后做一道例题 #include <iostream> #include <cstring> #include <cstdio> #include <cmath> using namespace std; typedef long long ll; int T, n, m, uu, vv; double w[15][15]; const double eps=1e-7; void gauss(){ n--; for…

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 <…

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…

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…

https://blog.csdn.net/zhaoruixiang1111/article/details/79185927 为了学一个矩阵树定理 从行列式开始学(就当提前学线代了.. 论文生成树的计数及其应用 矩阵数定理: 截图来自于上述论文 裸题. #include<cstdio> #include<cstdlib> #include<cstring> #include<iostream> using namespace std; ; ; double…

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.…