PKU 2394

朴素的dijkstra算法，临街表实现

 1 #include<stdio.h>
 2 #include<string.h>
 3 #include<stdlib.h>
 4 #include<algorithm>
 5 #define Max 0x7FFFffff
 6 using namespace std;
 7 int a[505][505],dist[505];
 8 void dij(int n)
 9 {
10      int i,j,s[505],neww;
11     for(i=1;i<=n;i++)
12     {
13         dist[i]=a[1][i];
14             s[i]=1;
15         }
16         dist[1]=0;
17         s[1]=0;
18         for(i=0;i<n-1;i++)
19         {
20             int temp=Max;
21             int u=1;
22             for(j=1;j<=n;j++)
23                 if(s[j]==1&&dist[j]<temp)
24                 {
25                     u=j;
26                 temp=dist[j];
27                 }
28 
29         s[u]=0;
30         for(int j=1;j<=n;j++)
31             if(s[j]==1&&a[u][j]<Max)
32             {
33                 neww=dist[u]+a[u][j];
34                 if(neww<dist[j])
35                     dist[j]=neww;
36 
37             }
38         }
39 
40 }
41 int main()
42 {
43     int n,m,i,j,x,y,min,p,z,res[505],l;
44     scanf("%d %d %d %d",&n,&m,&p,&l);
45         memset(a,0,sizeof(a));
46          memset(dist,0,sizeof(dist));
47          memset(res,0,sizeof(res));
48         for(i=1;i<=n;i++)
49             for(j=1;j<=n;j++)
50             {
51                 a[i][j]=Max;
52                 if(i==j)
53                 a[i][j]=0;
54             }
55             while(m--)
56             {
57                 scanf("%d %d %d",&x,&y,&z);
58                 if(z<a[x][y])
59                     a[x][y]=a[y][x]=z;
60             }
61             dij(n);
62             int count=0;i=0;
63             for(j=1;j<=p;j++)
64             {
65                 scanf("%d",&x);
66                 if(dist[x]<=l)
67                 {
68                     res[i++]=j;
69                     count++;
70                 }
71 
72             }
73             printf("%d\n",count);
74             for(j=0;j<i;j++)
75             {
76                 printf("%d\n",res[j]);
77             }
78             return 0;
79         
80 
81         
82 }
83