Funny Car Racing CSU - 1333 （spfa）

There is a funny car racing in a city with n junctions and m directed roads.

The funny part is: each road is open and closed periodically. Each road is associate with two integers (a, b), that means the road will be open for a seconds, then closed for b seconds, then open for a seconds… All these start from the beginning of the race. You must enter a road when it’s open, and leave it before it’s closed again.

Your goal is to drive from junction s and arrive at junction t as early as possible. Note that you can wait at a junction even if all its adjacent roads are closed.

Input
There will be at most 30 test cases. The first line of each case contains four integers n, m, s, t (1<=n<=300, 1<=m<=50,000, 1<=s,t<=n). Each of the next m lines contains five integers u, v, a, b, t (1<=u,v<=n, 1<=a,b,t<=105), that means there is a road starting from junction u ending with junction v. It’s open for a seconds, then closed for b seconds (and so on). The time needed to pass this road, by your car, is t. No road connects the same junction, but a pair of junctions could be connected by more than one road.

Output
For each test case, print the shortest time, in seconds. It’s always possible to arrive at t from s.

Sample Input

3 2 1 3
1 2 5 6 3
2 3 7 7 6
3 2 1 3
1 2 5 6 3
2 3 9 5 6
Sample Output

Case 1: 20
Case 2: 9

#include<map>
#include<queue>
#include<stack>
#include<vector>
#include<math.h>
#include<cstdio>
#include<sstream>
#include<numeric>//STL数值算法头文件
#include<stdlib.h>
#include <ctype.h>
#include<string.h>
#include<iostream>
#include<algorithm>
#include<functional>//模板类头文件
using namespace std;

typedef long long ll;
const int maxn=1100;
const int INF=0x3f3f3f3f;

struct node
{
    ll to, next ;
    ll a, b, c, d ;
} E[50010];

ll id, head[maxn] ;
ll dis[maxn] ;
bool vis[maxn];

void init()
{
    id = 0;
    memset(head, -1, sizeof(head));
    for(ll i = 0 ; i < maxn ; i++)
        dis[i] = INF ;
}

void addEdg(ll u, ll v, ll a, ll b, ll c)
{
    E[id].to = v ;
    E[id].a = a ;
    E[id].b = b ;
    E[id].c = c ;
    E[id].d = a + b ;
    E[id].next = head[u] ;
    head[u] = id++;
}
void spfa(ll s, ll t)
{
    memset(vis,0,sizeof(vis));
    queue<ll>q;
    dis[s] = 0 ;
    vis[s]=1;
    if(s != t )
        q.push( s ) ;
    while(!q.empty())
    {
        ll u = q.front() ;
        q.pop() ;
        vis[u] = 0 ;
        for(ll i = head[u] ; i!=-1; i=E[i].next)
        {
            ll v = E[i].to ;
            ll tt = E[i].a - (dis[u]%E[i].d);
            if(tt<E[i].c)
                tt += E[i].b ;
            else
                tt = 0 ;
            if(dis[v] > dis[u] + tt +E[i].c)
            {
                dis[v] = dis[u] + tt +E[i].c ;
                if(!vis[v]&&v!=t)
                {
                    vis[v] = 1; 
                    q.push(v);
                }
            }
        }
    }
}

int main()
{
    ll n, m, s, t, u, v, a, b, c ;
    ll T = 0;
    while(~scanf("%lld%lld%lld%lld",&n,&m,&s,&t))
    {
        init();
        while(m--)
        {
            scanf("%lld%lld%lld%lld%lld",&u, &v, &a, &b, &c) ;
            if(c<=a)
                addEdg( u, v, a, b, c );
        }
        spfa(s, t ) ;
        if(dis[t]==INF)
            dis[t] = -1;
        printf("Case %lld: %lld\n",++T,dis[t]);
    }
}