博客
关于我
强烈建议你试试无所不能的chatGPT,快点击我
CF721C. Journey[DP DAG]
阅读量:6981 次
发布时间:2019-06-27

本文共 3262 字,大约阅读时间需要 10 分钟。

C. Journey
time limit per test
3 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Recently Irina arrived to one of the most famous cities of Berland — the Berlatov city. There are n showplaces in the city, numbered from 1 to n, and some of them are connected by one-directional roads. The roads in Berlatov are designed in a way such that there are nocyclic routes between showplaces.

Initially Irina stands at the showplace 1, and the endpoint of her journey is the showplace n. Naturally, Irina wants to visit as much showplaces as she can during her journey. However, Irina's stay in Berlatov is limited and she can't be there for more than T time units.

Help Irina determine how many showplaces she may visit during her journey from showplace 1 to showplace n within a time not exceeding T. It is guaranteed that there is at least one route from showplace 1 to showplace n such that Irina will spend no more than Ttime units passing it.

Input

The first line of the input contains three integers n, m and T (2 ≤ n ≤ 5000,  1 ≤ m ≤ 5000,  1 ≤ T ≤ 109) — the number of showplaces, the number of roads between them and the time of Irina's stay in Berlatov respectively.

The next m lines describes roads in Berlatov. i-th of them contains 3 integers ui, vi, ti (1 ≤ ui, vi ≤ n, ui ≠ vi, 1 ≤ ti ≤ 109), meaning that there is a road starting from showplace ui and leading to showplace vi, and Irina spends ti time units to pass it. It is guaranteed that the roads do not form cyclic routes.

It is guaranteed, that there is at most one road between each pair of showplaces.

Output

Print the single integer k (2 ≤ k ≤ n) — the maximum number of showplaces that Irina can visit during her journey from showplace 1 to showplace n within time not exceeding T, in the first line.

Print k distinct integers in the second line — indices of showplaces that Irina will visit on her route, in the order of encountering them.

If there are multiple answers, print any of them.

Examples
input
4 3 13 1 2 5 2 3 7 2 4 8
output
3 1 2 4
input
6 6 7 1 2 2 1 3 3 3 6 3 2 4 2 4 6 2 6 5 1
output
4 1 2 4 6
input
5 5 6 1 3 3 3 5 3 1 2 2 2 4 3 4 5 2
output
3 1 3 5

题意:单向,没有回路,没有重边自环,限制时间,求1到n最多经过几个点,并输出这些点任意方案

因为没有环,又保证1和n连通,一开始想树形DP,并不好做,然后发现这是有向边 突然发现,这不就是有向无环图,有向无环图DAG的最短路最长路可以用DP来做,扩展一下应该也可以 f[i][j]表示从i到n经过j个点的时间 PS:因为忘判vis TLE一次
////  main.cpp//  c////  Created by Candy on 9/30/16.//  Copyright © 2016 Candy. All rights reserved.//#include 
#include
#include
#include
#include
#include
using namespace std;const int N=5005,M=5005,INF=1e9+5;inline int read(){ char c=getchar();int x=0,f=1; while(c<'0'||c>'9'){ if(c=='-')f=-1;c=getchar();} while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();} return x;}int n,m,T,u,v,w;struct edge{ int v,w,ne;}e[M<<1];int h[N],cnt=0;void ins(int u,int v,int w){ cnt++; e[cnt].v=v;e[cnt].w=w;e[cnt].ne=h[u];h[u]=cnt;}int f[N][N],vis[N];void dp(int u){ if(u==n) return; int child=0; if(vis[u]) return; vis[u]=1; for(int i=h[u];i;i=e[i].ne){ child++; int v=e[i].v,w=e[i].w; dp(v); for(int j=1;j<=n;j++) if(f[v][j-1]
=1;i--) if(f[1][i]<=T) {num=i;break;} printf("%d\n",num); print(1,num); return 0;}

 

转载地址:http://mvjpl.baihongyu.com/

你可能感兴趣的文章
IMAP和POP3区别
查看>>
验证码
查看>>
linux 测试机器间的带宽(iperf)
查看>>
Vmware vCenter 配置分布式交换机
查看>>
Eclipse CDT标准库头文件设置
查看>>
IntelliJ IDEA 乱码解决方案 (项目代码、控制台等)
查看>>
加了个油
查看>>
ruby 调用Linux 系统变量
查看>>
我的友情链接
查看>>
(改进版)jQuery表单验证插件formValidator
查看>>
linux常用命令(2)
查看>>
PHP 学习笔记 (2)
查看>>
《java数据结构和算法》读书笔记
查看>>
我的友情链接
查看>>
FST的简单应用
查看>>
数据趋势拟合--多项式拟合
查看>>
Hyper-V内存获取模式 内存权重
查看>>
linux系统时钟和硬件时钟
查看>>
阅读基地畅销榜数据抓取
查看>>
使用maven3生成自定义的archetype
查看>>