题意弄了半天: 给出一个有向图,带边权,src,dst. 求出src到dst的最大流,再求出从src到dst流量最大的路径的流量,求它们的比值. #include <cstdio> #include <cstring> #include <queue> #include <vector> #define oo 0x3f3f3f3f #define maxn 1010 using namespace std; struct Edge { int u, v, f…

Route Redundancy Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 625    Accepted Submission(s): 367 Problem Description A city is made up exclusively of one-way steets.each street in the city ha…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4240 A city is made up exclusively of one-way steets.each street in the city has a capacity,which is the minimum of the capcities of the streets along that route. The redundancy ratio from point A to poi…

http://acm.hdu.edu.cn/showproblem.php?pid=4240 题意:求最大流和流量最大的一条路径的流量的比值 题解:流量最大的路径的流量在dinic的dfs每次搜到终点的时候更新最大值 #include <cstdio> #include <cstring> #include <cstdlib> #include <iostream> #include <algorithm> using namespace std…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4240 思路:题意真的有点难理解:在城市A->B之间通过所有路径一小时之内能通过最大的车辆(Maxflow)/所有边上通过最大车流量(cap)的那条叫做redundancy ratio.最小的redundancy ratio是前者最大的车流量的那一条(cap),问minimum redundancy ratio是多少. 其实就是跑一次最大流,每当找到一条增广路时,记录此时的cap,然后取最大的就行了.…

Route Redundancy Time Limit: 1000ms Memory Limit: 32768KB This problem will be judged on HDU. Original ID: 424064-bit integer IO format: %I64d      Java class name: Main   A city is made up exclusively of one-way steets.each street in the city has a…

题目大意就是给出一个矩阵,每个格子里面要么是0, 要么是1:是否能够经过交换(交换行或者列)使得主对角线上都是1. 其实就行和列的匹配,左边是行,右边是列,然后如果行列交点是1,那么就可以匹配,看是否为完美匹配,然后输出怎么交换的.开始很蒙的,后来仔细去 想,可以这样理解,想要对角线上都是1,那么我们就可以锁定行,来选择列和它匹配,将选择的列移动到和该行形成对角线上是1的位置,比如和第一行匹配的 列,就要移动要第一列,第二行的,就到第二列.其实就是对第i行,找一个第i个数是1的列和它匹配,然后看…

[题目]2017"百度之星"程序设计大赛 - 初赛(A) [题意]给定n个点的带边权树,m条编号1~m的路径,Q次询问编号区间[L,R]所有链的交集的长度.n<=500000. [算法]线段树+RMQ-LCA+树链的交 [题解]树链的交:记一条链为(a1,b1),LCA为c1.另一条链为(a2,b2),LCA为c2.记a1a2,a1b2,b1a2,b1b2的LCA为d1,d2,d3,d4,按深度排序后得deep[d1]<=deep[d2]<=deep[d3]<=…

Ignatius and the Princess I Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 17171    Accepted Submission(s): 5495Special Judge Problem Description The Princess has been abducted by the BEelzebub…

思路:将每个关系当成一条有向边,查询时就判断之间存在路径. #include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<string> #include<map> #define Maxn 210 using namespace std; map<string,int> g; map<string,int> ver…