1205. By the Underground or by Foot?(ｓｐｆａ）

１２０５

简单题　有一些小细节　两个站可能不相连　但是可以走过去

  1 #include <iostream>

  2 #include<cstdio>

  3 #include<cstring>

  4 #include<algorithm>

  5 #include<stdlib.h>

  6 #include<vector>

  7 #include<queue>

  8 #include<cmath>

  9 using namespace std;

 10 #define INF 0xfffffff

 11 vector<int>ed[310];

 12 double v1,v2,x[310],y[310],w[210][210],dis[210];

 13 int n,vis[210],pa[210],o[210];

 14 void spfa(int s,int e)

 15 {

 16     int i;

 17     for(i =0 ; i <= n ; i++)

 18     dis[i] = INF;

 19     dis[s] = 0;

 20     queue<int>q;

 21     vis[s] = 1;

 22     q.push(s);

 23     while(!q.empty())

 24     {

 25         int u  = q.front();

 26         q.pop();

 27         vis[u] = 0;

 28         for(i = 0 ; i < (int)ed[u].size() ; i++)

 29         {

 30             int v = ed[u][i];

 31             if(dis[v]>dis[u]+w[u][v])

 32             {

 33                 pa[v] = u;

 34                 dis[v] = dis[u]+w[u][v];

 35                 if(!vis[v])

 36                 {

 37                     vis[v] = 1;

 38                     q.push(v);

 39                 }

 40             }

 41         }

 42     }

 43     printf("%.7lf\n",dis[e]);

 44     int g = 0,x=e;

 45     while(pa[x]!=s)

 46     {

 47         x = pa[x];

 48         g++;

 49         o[g] = x;

 50     }

 51     printf("%d",g);

 52     for(i = g ; i>=1 ; i--)

 53     printf(" %d",o[i]);

 54     puts("");

 55 }

 56 double dist(int u,int v)

 57 {

 58     double s = sqrt((x[u]-x[v])*(x[u]-x[v])+(y[u]-y[v])*(y[u]-y[v]));

 59     return s;

 60 }

 61 int main()

 62 {

 63     int i,j,u,v;

 64     cin>>v1>>v2;

 65     cin>>n;

 66     for(i = 1; i <= n ;i++)

 67     {

 68         scanf("%lf%lf",&x[i],&y[i]);

 69     }

 70     for(i = 0 ;i <= n+1 ; i++)

 71         for(j = 0  ; j <= n+1 ; j++)

 72         w[i][j] = INF;

 73     while(scanf("%d%d",&u,&v)!=EOF)

 74     {

 75         if(!u&&!v)

 76         break;

 77         w[u][v] = dist(u,v)/v2;

 78         w[v][u] = w[u][v];

 79         ed[u].push_back(v);

 80         ed[v].push_back(u);

 81     }

 82     for(i = 1; i <= n ; i++)

 83         for(j = i+1 ;j <= n ;j++)

 84         {

 85             if(w[i][j]==INF)

 86             {

 87                 w[i][j] = dist(i,j)/v1;

 88                 w[j][i] = w[i][j]/v1;

 89                 ed[i].push_back(j);

 90                 ed[j].push_back(i);

 91             }

 92         }

 93     scanf("%lf%lf%lf%lf",&x[0],&y[0],&x[n+1],&y[n+1]);

 94     for(i = 1; i <= n+1 ;i++)

 95     {

 96         w[0][i] = dist(i,0)/v1;

 97         w[i][0] = w[0][i];

 98         ed[0].push_back(i);

 99         ed[i].push_back(0);

100         w[n+1][i] = dist(i,n+1)/v1;

101         w[i][n+1] = w[n+1][i];

102         ed[i].push_back(n+1);

103         ed[n+1].push_back(i);

104     }

105     n++;

106     for(i = 0; i <= n ;i++)

107     w[i][i] = 0;

108     spfa(0,n);

109     return 0;

110 }

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