POJ 1364 King (差分约束)
|
King
Description Once, in one kingdom, there was a queen and that queen was expecting a baby. The queen prayed: ``If my child was a son and if only he was a sound king.'' After nine months her child was born, and indeed, she gave birth to a nice son.
Unfortunately, as it used to happen in royal families, the son was a little retarded. After many years of study he was able just to add integer numbers and to compare whether the result is greater or less than a given integer number. In addition, the numbers had to be written in a sequence and he was able to sum just continuous subsequences of the sequence. The old king was very unhappy of his son. But he was ready to make everything to enable his son to govern the kingdom after his death. With regards to his son's skills he decided that every problem the king had to decide about had to be presented in a form of a finite sequence of integer numbers and the decision about it would be done by stating an integer constraint (i.e. an upper or lower limit) for the sum of that sequence. In this way there was at least some hope that his son would be able to make some decisions. After the old king died, the young king began to reign. But very soon, a lot of people became very unsatisfied with his decisions and decided to dethrone him. They tried to do it by proving that his decisions were wrong. Therefore some conspirators presented to the young king a set of problems that he had to decide about. The set of problems was in the form of subsequences Si = {aSi, aSi+1, ..., aSi+ni} of a sequence S = {a1, a2, ..., an}. The king thought a minute and then decided, i.e. he set for the sum aSi + aSi+1 + ... + aSi+ni of each subsequence Si an integer constraint ki (i.e. aSi + aSi+1 + ... + aSi+ni < ki or aSi + aSi+1 + ... + aSi+ni > ki resp.) and declared these constraints as his decisions. After a while he realized that some of his decisions were wrong. He could not revoke the declared constraints but trying to save himself he decided to fake the sequence that he was given. He ordered to his advisors to find such a sequence S that would satisfy the constraints he set. Help the advisors of the king and write a program that decides whether such a sequence exists or not. Input The input consists of blocks of lines. Each block except the last corresponds to one set of problems and king's decisions about them. In the first line of the block there are integers n, and m where 0 < n <= 100 is length of the sequence S and 0 < m <= 100 is the number of subsequences Si. Next m lines contain particular decisions coded in the form of quadruples si, ni, oi, ki, where oi represents operator > (coded as gt) or operator < (coded as lt) respectively. The symbols si, ni and ki have the meaning described above. The last block consists of just one line containing 0.
Output The output contains the lines corresponding to the blocks in the input. A line contains text successful conspiracy when such a sequence does not exist. Otherwise it contains text lamentable kingdom. There is no line in the output corresponding to the last ``null'' block of the input.
Sample Input 4 2 Sample Output lamentable kingdom Source |
差分约束判是否有负环
设S[j]=a0+a1+a2+...+aj
由题意:S[si+ni]-S[si-1]>k或S[si+ni]-S[si-1]<k,由于差分约束系统只能解决>=和<=的情况,要把>k转换成>=k+1,<k转换成<=k-1
差分约束加入附加源点是为了保证图的连通性,但也可以不加附加源点,而是一开始把所有顶点都入队,并设dis为0(这个时候不算入队次数),相当于超级源点的权值
#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<cmath> using namespace std; const int N=;
const int INF=0x3f3f3f3f; struct Edge{
int to,nxt;
int cap;
}edge[N*N]; int n,m,cnt,head[N];
int dis[N],vis[N],count[N]; void addedge(int cu,int cv,int cw){
edge[cnt].to=cv; edge[cnt].cap=cw; edge[cnt].nxt=head[cu];
head[cu]=cnt++;
} int SPFA(){
queue<int> q;
while(!q.empty())
q.pop();
int limit=(int)sqrt(1.0*n);
memset(vis,,sizeof(vis));
memset(count,,sizeof(count));
for(int i=;i<=n;i++){
dis[i]=;
q.push(i);
//vis[i]=1;
}
while(!q.empty()){
int u=q.front();
q.pop();
vis[u]=;
for(int i=head[u];i!=-;i=edge[i].nxt){
int v=edge[i].to;
if(dis[v]>dis[u]+edge[i].cap){
dis[v]=dis[u]+edge[i].cap;
if(!vis[v]){
vis[v]=;
if(++count[v]>limit)
return ;
q.push(v);
}
}
}
}
return ;
} int main(){ //freopen("input.txt","r",stdin); while(~scanf("%d",&n) && n){
cnt=;
memset(head,-,sizeof(head));
scanf("%d",&m);
int u,v,w;
char op[];
while(m--){
scanf("%d%d%s%d",&u,&v,op,&w);
if(op[]=='g')
addedge(v+u,u-,-w-);
else
addedge(u-,u+v,w-);
}
if(SPFA())
puts("lamentable kingdom");
else
puts("successful conspiracy");
}
return ;
}
POJ 1364 King (差分约束)的更多相关文章
- POJ 1364 King --差分约束第一题
题意:求给定的一组不等式是否有解,不等式要么是:SUM(Xi) (a<=i<=b) > k (1) 要么是 SUM(Xi) (a<=i<=b) < k (2) 分析 ...
- [poj 1364]King[差分约束详解(续篇)][超级源点][SPFA][Bellman-Ford]
题意 有n个数的序列, 下标为[1.. N ], 限制条件为: 下标从 si 到 si+ni 的项求和 < 或 > ki. 一共有m个限制条件. 问是否存在满足条件的序列. 思路 转化为差 ...
- poj 1364 King(差分约束)
题目:http://poj.org/problem?id=1364 #include <iostream> #include <cstdio> #include <cst ...
- POJ 1364 King (UVA 515) 差分约束
http://poj.org/problem?id=1364 http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemi ...
- poj 1364 King(差分约束)
题意(真坑):傻国王只会求和,以及比较大小.阴谋家们想推翻他,于是想坑他,上交了一串长度为n的序列a[1],a[2]...a[n],国王作出m条形如(a[si]+a[si+1]+...+a[si+ni ...
- POJ 1364 King
http://poj.org/problem?id=1364 题意 :给出一个序列a1,a2,a3,a4.....ai,......at ;然后给你一个不等式使得ai+a(i+1)+a(i+2)+.. ...
- poj 1201 Intervals(差分约束)
题目:http://poj.org/problem?id=1201 题意:给定n组数据,每组有ai,bi,ci,要求在区间[ai,bi]内至少找ci个数, 并使得找的数字组成的数组Z的长度最小. #i ...
- poj 1201 Intervals——差分约束裸题
题目:http://poj.org/problem?id=1201 差分约束裸套路:前缀和 本题可以不把源点向每个点连一条0的边,可以直接把0点作为源点.这样会快许多! 可能是因为 i-1 向 i 都 ...
- POJ——1364King(差分约束SPFA判负环+前向星)
King Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 11946 Accepted: 4365 Description ...
随机推荐
- 【BZOJ】【2741】【FOTILE模拟赛】L
可持久化Trie+分块 神题……Orz zyf & lyd 首先我们先将整个序列搞个前缀异或和,那么某一段的异或和,就变成了两个数的异或和,所以我们就将询问[某个区间中最大的区间异或和]改变成 ...
- UI_UITabBarController
建立控制器 // 普通控制器 GroupViewController *groupVC = [[GroupViewController alloc] init]; SecondViewControll ...
- Java实现将Excel导入数据库和从数据库中导出为Excel
实现的功能: 用Java实现从Excel导入数据库,如果存在就更新 将数据库中的数据导出为Excel 1.添加jxl.jar mysql-connector-java.1.7-bin.jar包到项目的 ...
- OpenCV学习(17) 细化算法(5)
本章我们看下Pavlidis细化算法,参考资料http://www.imageprocessingplace.com/downloads_V3/root_downloads/tutorials/con ...
- go语言基础之append扩容特点
1.append扩容特点 示例: package main //必须有个main包 import "fmt" func main() { //如果超过原来的容量,通常以2倍容量扩容 ...
- Java基础(十二):包(package)
一.Java 包(package): 为了更好地组织类,Java 提供了包机制,用于区别类名的命名空间.包的作用: 1.把功能相似或相关的类或接口组织在同一个包中,方便类的查找和使用. 2.如同文件夹 ...
- GDB调试工具总结
程序调试的基本思想是“分析现象->假设错误原因->产生新的现象去验证假设”这样一个循环过程,根据现象如何假设错误原因,以及如何设计新的现象去验证假设,需要非常严密的分析和思考.程序中除了一 ...
- Android GUI之Window、WindowManager
通过前几篇的文章(查看系列文章:http://www.cnblogs.com/jerehedu/p/4607599.html#gui ),我们清楚了Activity实际上是将视图的创建和显示交给了Wi ...
- Redis自学笔记—PHP
connect 实例连接到一个Redis. $redis = new redis(); $result = $redis->connect('127.0.0.1', 6379); var_dum ...
- CKEditor && CKFinder 配置
准备 ...