//spfa 判断正环 #include<iostream> #include<queue> #include<cstring> using namespace std; const int N=1e4; const int INF=2e9; int h[N],to[N],ne[N],idx; double r[N],c[N]; int n, m,X; double V; void add(int u,int v,double r1,double c1) { to[id…

题目链接:Currency Exchange 题意: 钱的种类为N,M条命令,拥有种类为S这类钱的数目为V,命令为将a换成b,剩下的四个数为a对b的汇率和a换成b的税,b对a的汇率和b换成a的税,公式为(钱数-税)*汇率,问最后钱的数目是否会增多 题解: 这是我第一道SPFA,这题算是SPFA的模板题吧.找令价值最大的最长路径. #include<cstdio> #include<iostream> #include<vector> #include<algori…

题意:给出n种货币,m中交换关系,给出两种货币汇率和手续费,求能不能通过货币间的兑换使财富增加. 用Bellman_Ford 求出是否有正环,如果有的话就可以无限水松弛,财富可以无限增加. #include<string.h> #include<stdio.h> const int N=110; const int inf=0x3fffffff; int start,num,n; double dist[N],wf; struct edge { int st,ed; double…

Several currency exchange points are working in our city. Let us suppose that each point specializes in two particular currencies and performs exchange operations only with these currencies. There can be several points specializing in the same pair o…

Description Several currency exchange points are working in our city. Let us suppose that each point specializes in two particular currencies and performs exchange operations only with these currencies. There can be several points specializing in the…

Farmer John has decided to reward his cows for their hard work by taking them on a tour of the big city! The cows must decide how best to spend their free time. Fortunately, they have a detailed city map showing the L (2 ≤ L ≤ 1000) major landmarks (…

链接: http://poj.org/problem?id=1860 Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 23261   Accepted: 8419 Description Several currency exchange points are working in our city. Let us suppose that each point specializes in two particular…

XYZZY Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4421    Accepted Submission(s): 1252 Problem Description It has recently been discovered how to run open-source software on the Y-Crate gami…

XYZZY Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 5304    Accepted Submission(s): 1510 Problem Description It has recently been discovered how to run open-source software on the Y-Crate gam…

Description Several currency exchange points are working in our city. Let us suppose that each point specializes in two particular currencies and performs exchange operations only with these currencies. There can be several points specializing in the…