UVa 12661 Funny Car Racing【 dijkstra 】

 1 #include<iostream>  
 2 #include<cstdio>  
 3 #include<cstring> 
 4 #include <cmath> 
 5 #include<stack>
 6 #include<vector>
 7 #include<map> 
 8 #include<set>
 9 #include<queue> 
10 #include<algorithm>  
11 using namespace std;
12 
13 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)
14 
15 typedef long long LL;
16 const int INF = (1<<30)-1;
17 const int mod=1000000007;
18 const int maxn=100005;
19 
20 int d[maxn],used[maxn],next[maxn],first[maxn];
21 int n,m,ecnt,s,t;
22 
23 struct edge{
24     int v,a,b,t;
25 } e[maxn];
26 
27 void addedge(int u,int v,int a,int b,int t){
28     next[++ecnt]=first[u];
29     e[ecnt].v=v;
30     e[ecnt].a=a;
31     e[ecnt].b=b;
32     e[ecnt].t=t;
33     first[u]=ecnt;
34 }
35 
36 void dijkstra(int s){
37     for(int i=1;i<=n;i++) d[i]=INF;
38     d[s]=0;
39     memset(used,0,sizeof(used));
40     
41     for(int k=1;k<=n;k++){
42         int u,m=INF;
43         for(int i=1;i<=n;i++) if(!used[i]&&d[i]<m) m=d[u=i];
44         used[u]=1;
45         for(int i=first[u];i!=-1;i=next[i]){
46             int v=e[i].v,a=e[i].a,b=e[i].b,t=e[i].t;
47             
48             if(a<t) continue;//打开的时间小于通过的时间 
49             
50             int now=d[u]%(a+b);
51             if(now+t<=a){//现在能够通过的情况下松弛 
52                 if(d[v]>d[u]+t) d[v]=d[u]+t;
53             }
54             else{
55                 int wait=a+b-now;//现在需要等待的情况下松弛 
56                 if(d[v]>d[u]+wait+t) d[v]=d[u]+wait+t;
57             }            
58         }
59     }    
60     
61 }
62 
63 int main(){
64     int kase=0;
65     while(scanf("%d %d %d %d",&n,&m,&s,&t)!=EOF){
66         memset(first,-1,sizeof(first));
67         ecnt=0;
68         
69         while(m--){
70             int u,v,a,b,t;
71             cin>>u>>v>>a>>b>>t;
72             addedge(u,v,a,b,t);
73         }
74         dijkstra(s);
75         
76         printf("Case %d: ",++kase);
77         printf("%d\n",d[t]);
78     }
79     return 0;
80 }