(hdu-4280)Island Transport~测试网络流模板速度~要加挂才能过啊
You have a transportation company there. Some routes are opened for passengers. Each route is a straight line connecting two different islands, and it is bidirectional. Within an hour, a route can transport a certain number of passengers in one direction. For safety, no two routes are cross or overlap and no routes will pass an island except the departing island and the arriving island. Each island can be treated as a point on the XY plane coordinate system. X coordinate increase from west to east, and Y coordinate increase from south to north.
The transport capacity is important to you. Suppose many passengers depart from the westernmost island and would like to arrive at the easternmost island, the maximum number of passengers arrive at the latter within every hour is the transport capacity. Please calculate it.
Then T test cases follow. The first line of each test case contains two integers N and M (2<=N,M<=100000), the number of islands and the number of routes. Islands are number from 1 to N.
Then N lines follow. Each line contain two integers, the X and Y coordinate of an island. The K-th line in the N lines describes the island K. The absolute values of all the coordinates are no more than 100000.
Then M lines follow. Each line contains three integers I1, I2 (1<=I1,I2<=N) and C (1<=C<=10000) . It means there is a route connecting island I1 and island I2, and it can transport C passengers in one direction within an hour.
It is guaranteed that the routes obey the rules described above. There is only one island is westernmost and only one island is easternmost. No two islands would have the same coordinates. Each island can go to any other island by the routes.
6
#include<stdio.h>
#include<string>
#include<string.h>
#include<vector>
#include<queue>
using namespace std;
#pragma comment(linker, "/STACK:1024000000,1024000000")
const int maxn = 1e5 + ;
const int INF = ;
struct node {
int from, to, cap, flow;
};
struct Dinic {
int n, m, s, t;
vector<node>nodes;
vector<int>g[maxn];
int vis[maxn];
int d[maxn];
int cur[maxn];
void clearall(int n) {
for (int i = ; i < n ; i++) g[i].clear();
nodes.clear();
}
void clearflow() {
int len = nodes.size();
for (int i = ; i < len ; i++) nodes[i].flow = ;
}
void add(int from, int to, int cap) {
nodes.push_back((node) {
from, to, cap,
});
nodes.push_back((node) {
to, from, cap,
});
m = nodes.size();
g[from].push_back(m - );
g[to].push_back(m - );
}
bool bfs() {
memset(vis, , sizeof(vis));
queue<int>q;
q.push(s);
d[s] = ;
vis[s] = ;
while(!q.empty()) {
int x = q.front();
q.pop();
int len = g[x].size();
for (int i = ; i < len ; i++) {
node &e = nodes[g[x][i]];
if (!vis[e.to] && e.cap > e.flow ) {
vis[e.to] = ;
d[e.to] = d[x] + ;
q.push(e.to);
}
}
}
return vis[t];
}
int dfs(int x, int a) {
if (x == t || a == ) return a;
int flow = , f, len = g[x].size();
for (int &i = cur[x] ; i < len ; i++) {
node & e = nodes[g[x][i]];
if (d[x] + == d[e.to] && (f = dfs(e.to, min(a, e.cap - e.flow))) > ) {
e.flow += f;
nodes[g[x][i] ^ ].flow -= f;
flow += f;
a -= f;
if (a == ) break;
}
}
return flow;
}
int maxflow(int a, int b) {
s = a;
t = b;
int flow = ;
while(bfs()) {
memset(cur, , sizeof(cur));
flow += dfs(s, INF);
}
return flow;
}
vector<int>mincut() {
vector<int>ans;
int len = nodes.size();
for (int i = ; i < len ; i++) {
node & e = nodes[i];
if ( vis[e.from] && !vis[e.to] && e.cap > ) ans.push_back(i);
}
return ans;
}
void reduce() {
int len = nodes.size();
for (int i = ; i < len ; i++) nodes[i].cap -= nodes[i].flow;
}
} f;
int main() {
int n, m, t;
scanf("%d", &t);
while(t--) {
scanf("%d%d", &n, &m);
f.clearall(n);
f.clearflow();
int left = INF, right = -INF, s = , t = ;
for (int i = ; i <= n ; i++) {
int x, y;
scanf("%d%d", &x, &y);
if (x < left) {
left = x;
s = i;
}
if (x > right) {
right = x;
t = i;
}
}
for (int i = ; i < m ; i++) {
int u, v, c;
scanf("%d%d%d", &u, &v, &c);
f.add(u, v, c);
}
printf("%d\n", f.maxflow(s, t));
}
return ;
}
(hdu-4280)Island Transport~测试网络流模板速度~要加挂才能过啊的更多相关文章
- HDU 4280 Island Transport(网络流,最大流)
HDU 4280 Island Transport(网络流,最大流) Description In the vast waters far far away, there are many islan ...
- HDU 4280 Island Transport
Island Transport Time Limit: 10000ms Memory Limit: 65536KB This problem will be judged on HDU. Origi ...
- Hdu 4280 Island Transport(最大流)
Island Transport Time Limit: 20000/10000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Other ...
- HDU 4280 Island Transport(无向图最大流)
HDU 4280:http://acm.hdu.edu.cn/showproblem.php?pid=4280 题意: 比较裸的最大流题目,就是这是个无向图,并且比较卡时间. 思路: 是这样的,由于是 ...
- HDU 4280 Island Transport(dinic+当前弧优化)
Island Transport Description In the vast waters far far away, there are many islands. People are liv ...
- HDU 4280 Island Transport(网络流)
转载请注明出处:http://blog.csdn.net/u012860063 题目链接:pid=4280">http://acm.hdu.edu.cn/showproblem.php ...
- HDU 4280 Island Transport(HLPP板子)题解
题意: 求最大流 思路: \(1e5\)条边,偷了一个超长的\(HLPP\)板子.复杂度\(n^2 \sqrt{m}\).但通常在随机情况下并没有isap快. 板子: template<clas ...
- HDU 4280 ISAP+BFS 最大流 模板
Island Transport Time Limit: 20000/10000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Other ...
- HDU 4280:Island Transport(ISAP模板题)
http://acm.hdu.edu.cn/showproblem.php?pid=4280 题意:在最西边的点走到最东边的点最大容量. 思路:ISAP模板题,Dinic过不了. #include & ...
随机推荐
- Algorithm --> 投资组和求最大利润
投资组和求最大利润 题目: 投资人出资一笔费用mount,投资给不同的公司(A,B,C....),求最大获取利润? 例如:投资400百万,给出两家公司A和B: 1.如果投资一百万给A公司,投资3百万给 ...
- 套接字API
Q:套接字特点 A:管道,消息队列,信号量,共享内存这些通信机制只能允许同一计算机上运行的进程相互通信,而套接字不仅可以提供在同一计算机上的进程间通信,还可以提供不同计算机上的进程间通信. 服务器端: ...
- Oracle查询优化改写--------------------报表和数据仓库运算
一.行转列 二.列传行 '
- 程序猿媛 九:Adroid zxing 二维码3.1集成(源码无删减)
Adroid zxing 二维码3.1集成 声明:博文为原创,文章内容为,效果展示,思路阐述,及代码片段. 转载请保留原文出处“http://my.oschina.net/gluoyer/blog”, ...
- Go实现海量日志收集系统(二)
一篇文章主要是关于整体架构以及用到的软件的一些介绍,这一篇文章是对各个软件的使用介绍,当然这里主要是关于架构中我们agent的实现用到的内容 关于zookeeper+kafka 我们需要先把两者启动, ...
- WCF配置问题(配置WCF跨域)
其它的先放一边.今天先来分享一下前段时间给公司做网站WCF服务接口的心得. 配置文件的配置问题 这里既然讨论WCF配置文件的问题,那么怎么创建的就不一一讲解了.好多博主都有提过的.所以直接分享自己开发 ...
- 关于hbase中的hbase-site.xml 配置详解
该文档是用Hbase默认配置文件生成的,文件源是 hbase-default.xml hbase.rootdir 这个目录是region server的共享目录,用来持久化HBase.URL需要是'完 ...
- fcode-页面九宫格自动锁屏jquery插件
fcode.js 自动锁屏插件 fcode.js是什么? fcode.js是一款web页面九宫格自动锁屏js插件,依赖于jquery, 会在设置的范围里,判断用户有无操作,然后执行锁屏的功能. 就一个 ...
- C博客作业--指针
一.PTA实验作业 题目1:输出月份英文名 1. 本题PTA提交列表 2. 设计思路 3.代码截图 4.本题调试过程碰到问题及PTA提交列表情况说明. 选择这一题是因为这道题的通过率较低.为什么会这样 ...
- 学号:201621123032 《Java程序设计》第9周学习总结(
1:本周学习总结 1.1:以你喜欢的方式(思维导图或其他)归纳总结集合与泛型相关内容 2:书面作业 2.1: List中指定元素的删除(题集题目) 2.1.1:实验总结.并回答:列举至少2种在List ...