Va 12661 funny car racing

E-funny car racing

Time limit:1000 msMemory limit:0 KB64bit Io format:% LLD & % LlU

 

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.? RST 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? Ve 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 cocould 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

 

Problem solving: Dijkstra...

 

 1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cmath> 5 #include <algorithm> 6 #include <climits> 7 #include <vector> 8 #include <queue> 9 #include <cstdlib>10 #include <string>11 #include <set>12 #include <stack>13 #define LL long long14 #define pii pair<int,int>15 #define INF 0x3f3f3f3f16 using namespace std;17 const int maxn = 310;18 struct arc{19     int to,a,b,t,next;20     arc(int o = 0,int aa = 0,int bb = 0,int tt = 0,int z = -1){21         to = o;22         a = aa;23         b = bb;24         t = tt;25         next = z;26     }27 };28 arc e[51000];29 int head[maxn],tot,d[maxn],n;30 bool vis[maxn];31 void add(int u,int v,int a,int b,int t){32     e[tot] = arc(v,a,b,t,head[u]);33     head[u] = tot++;34 }35 priority_queue< pii,vector< pii >,greater< pii > >q;36 void dijkstra(int s){37     for(int i = 0; i <= n; ++i){38         d[i] = INF;39         vis[i] = false;40     }41     while(!q.empty()) q.pop();42     d[s] = 0;43     q.push(make_pair(d[s],s));44     while(!q.empty()){45         int u = q.top().second;46         q.pop();47         if(vis[u]) continue;48         vis[u] = true;49         for(int i = head[u]; ~i; i = e[i].next){50             int res = d[u]%(e[i].a + e[i].b);51             if(e[i].a - res >= e[i].t && d[e[i].to] > d[u] + e[i].t){52                 d[e[i].to] = d[u] + e[i].t;53                 q.push(make_pair(d[e[i].to],e[i].to));54             }else if(e[i].t <= e[i].a && d[e[i].to] > d[u] + e[i].t + e[i].a + e[i].b - res){55                 d[e[i].to] = d[u] + e[i].t + e[i].a + e[i].b - res;56                 q.push(make_pair(d[e[i].to],e[i].to));57             }58         }59     }60 61 }62 int main() {63     int m,s,t,a,b,u,v,w,cs = 1;64     while(~scanf("%d %d %d %d",&n,&m,&s,&t)){65         memset(head,-1,sizeof(head));66         for(int i = tot = 0; i < m; i++){67             scanf("%d %d %d %d %d",&u,&v,&a,&b,&w);68             add(u,v,a,b,w);69         }70         dijkstra(s);71         printf("Case %d: %d\n",cs++,d[t]);72     }73     return 0;74 }

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Va 12661 funny car racing