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…

//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…

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…

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…

Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 22111   Accepted: 7986 Description Several currency exchange points are working in our city. Let us suppose that each point specializes in two particular currencies and performs exchange op…

题目链接:https://vjudge.net/problem/POJ-1860 大致题意:有不同的货币,有很多货币交换点,每个货币交换点只能两种货币相互交换,有佣金C,汇率R. 每次交换算一次操作,问能不能经过一系列操作使得本来的货币的本金数额变大. 思路:相当于图,“一系列操作使得本金数额变大”说明有一个正的回路,能使得某种货币的数额增大,那么, 只要有这一个正的回路,那么我们一定可以让某种货币的数额变为无穷大,那么本来的货币的本金数额变大是一定的, 所有,我们只需要判断图中是否出现了一个正…

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…

Currency Exchange POJ - 1860 题意: 有许多货币兑换点,每个兑换点仅支持两种货币的兑换,兑换有相应的汇率和手续费.你有s这个货币 V 个,问是否能通过合理地兑换货币,使得你手中的货币折合成s后是有增加的. 思路: 这道题在建立每种货币的兑换关系后,找到图中的正环即可,因为你沿着正环跑就可以增加价值.这里可以用类似Bellman_Ford判断负环的方法. #include <algorithm> #include <iterator> #include &…

POJ 1860 Currency Exchange / ZOJ 1544 Currency Exchange (最短路径相关,spfa求环) 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 onl…

Currency Exchange Time Limit:1000MS     Memory Limit:30000KB     64bit IO Format:%I64d & %I64u Submit Status Practice POJ 1860 Description Several currency exchange points are working in our city. Let us suppose that each point specializes in two par…