称号:acdream 1211 Reactor Cooling 分类:无汇的有上下界网络流. 题意: 给n个点.及m根pipe,每根pipe用来流躺液体的.单向的.每时每刻每根pipe流进来的物质要等于流出去的物质,要使得m条pipe组成一个循环体.里面流躺物质. 而且满足每根pipe一定的流量限制,范围为[Li,Ri].即要满足每时刻流进来的不能超过Ri(最大流问题).同一时候最小不能低于Li. 比如: 个pipe) ,下界为1) 23 1 3 3 4 1 3 4 1 1 3 1 3 1 3…

题意:无源无汇有上下界的可行流 模型 思路:首先将所有边的容量设为上界减去下界,然后对一个点i,设i的所有入边的下界和为to[i],所有出边的下界和为from[i],令它们的差为dif[i]=to[i]-from[i],根据流量平衡原理,让出边和入边的下界相抵消,如果dif[i]>0,说明入边把出边的下界抵消了,还剩下dif[i]的流量必须要流过来(否则不满足入边的下界条件),这时从源点向i连一条容量为dif[i]的边来表示即可,如果dif[i]<0,同理应该从i向汇点连一条容量为-dif[i…

/* 题意:无源无汇,并且每条边的容量有上下界限的网络流问题!既然无源无汇,那么素有的节点都应该满足“入流==出流”! 输出每一条边的流量,使得满足上面的条件.(如果u->v有流量,那么v->u就不会有流量) 思路:如果增加了源点s和汇点t,对于u->v(下限为l, 上限为f) 将这一条边拆成3条,s->v(容量为l), u->v(容量为f-l) u->t(容量为l)这样就变成了每一个点的流入或者流出的流量至少是b!然后从s->t走一遍最大流,如果所有的附件边都已…

题目大概说一个核反应堆的冷却系统有n个结点,有m条单向的管子连接它们,管子内流量有上下界的要求,问能否使液体在整个系统中循环流动. 本质上就是求一个无源汇流量有上下界的容量网络的可行流,因为无源汇的容量网络上各个顶点都满足流量平衡条件,即所有点的∑流入流量=∑流出流量,可以看成里面的流是循环流动的,类似有向图欧拉回路. 而带上下界的网络可行流的求法,是根据网络流中一个流是可行流的充分必要条件——限制条件和平衡条件,去改造原网络,转化成不带下界的容量网络来求解的.数学模型那些证明之类的不难理解,见…

Reactor Cooling The terrorist group leaded by a well known international terrorist Ben Bladen is buliding a nuclear reactor to produce plutonium for the nuclear bomb they are planning to create. Being the wicked computer genius of this group, you are…

The terrorist group leaded by a well known international terrorist Ben Bladen is buliding a nuclear reactor to produce plutonium for the nuclear bomb they are planning to create. Being the wicked computer genius of this group, you are responsible for…

ZOJ 1314 Reactor Cooling | 上下界无源汇可行流 题意 有一个网络,每条边有流量的上界和下界,求一种方案,让里面的流可以循环往复地流动起来. 题解 上下界无源汇可行流的模型: 设置虚拟源点和虚拟汇点. 如果一条边\(u \to v\)的下界是\(mi\).上界是\(ma\),则在图中建一条\(u \to v\)的边,流量是\(ma - mi\),同时记录\(oud[u] += mi, ind[v] += mi\),分别代表\(u\)实际比图上多流出的流量与\(v\)实际比…

题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2314 The terrorist group leaded by a well known international terrorist Ben Bladen is buliding a nuclear reactor to produce plutonium for the nuclear bomb they are planning to create.…

Reactor Coolinghttp://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=1314 Time Limit: 5 Seconds      Memory Limit: 32768 KB      Special Judge The terrorist group leaded by a well known international terrorist Ben Bladen is buliding a nuclear re…

Reactor Cooling time limit per test: 0.5 sec. memory limit per test: 65536 KB input: standard output: standard The terrorist group leaded by a well known international terrorist Ben Bladen is buliding a nuclear reactor to produce plutonium for the nu…