HDU 1875 畅通工程再续

 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 long
14 #define pii pair<int,int>
15 #define pdi pair<double,int>
16 #define INF 999999
17 using namespace std;
18 const int maxn = 110;
19 int x[maxn],y[maxn],n;
20 double d[maxn],mp[maxn][maxn];
21 bool done[maxn];
22 priority_queue< pdi,vector< pdi >, greater< pdi > >q;
23 double calc(int i,int j){
24     double tmp = (x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]);
25     return sqrt(tmp);
26 }
27 void prim(){
28     while(!q.empty()) q.pop();
29     for(int i = 1; i <= n; i++){
30         d[i] = mp[1][i];
31         done[i] = false;
32         q.push(make_pair(d[i],i));
33     }
34     done[1] = true;//注意此处
35     double sum = 0;
36     bool flag = true;
37     while(!q.empty()){
38         int u = q.top().second;
39         double w = q.top().first;
40         q.pop();
41         if(done[u]) continue;
42         done[u] = true;
43         if(w >= INF){flag = false;break;}
44         sum += w;
45         for(int i = 1; i <= n; i++){
46             if(!done[i] && d[i] > mp[u][i]){
47                 d[i] = mp[u][i];
48                 q.push(make_pair(d[i],i));
49             }
50         }
51     }
52     if(flag) printf("%.1f\n",sum*100);
53     else puts("oh!");
54 }
55 int main() {
56     int t,i,j;
57     double tmp;
58     scanf("%d",&t);
59     while(t--){
60         scanf("%d",&n);
61         for(i = 1; i <= n; i++)
62             scanf("%d %d",x+i,y+i);
63         for(i = 1; i <= n; i++){
64             for(j = 1; j <= n; j++){
65                 tmp = calc(i,j);
66                 if(tmp < 10 || tmp > 1000) mp[i][j] = mp[j][i] = INF;
67                 else mp[i][j] = mp[j][i] = tmp;
68             }
69         }
70         prim();
71     }
72     return 0;
73 }