给出结点的坐标 以及已建好的边 要输出MST中加入的边(已建好的边就不用输出了)
结点的编号从1开始
注意这题只有一组数据 不能用多组输入 否则就超时（在这被坑惨了Orz）
Sample Input
9
1 5
0 0
3 2
4 5
5 1
0 4
5 2
1 2
5 3
3
1 3
9 7
1 2
Sample Output
1 6
3 7
4 9
5 7
8 3
1 # include <iostream> 2 # include <cstdio> 3 # include <cstring> 4 # include <algorithm> 5 # include <cmath> 6 # define LL long long 7 using namespace std ; 8 9 const int INF=0x3f3f3f3f; 10 const int MAXN=760; 11 bool vis[MAXN]; 12 double lowc[MAXN]; 13 int n ; 14 double cost[MAXN][MAXN] ; 15 int pre[MAXN] ; 16 17 struct poin 18 { 19 int x ; 20 int y ; 21 }p[MAXN]; 22 23 void Prim() 24 { 25 memset(vis,false,sizeof(vis)); 26 vis[1]=true; 27 for(int i=2;i<=n;i++) 28 { 29 lowc[i]=cost[1][i]; 30 pre[i] = 1 ; 31 } 32 33 for(int i=2;i<=n;i++) 34 { 35 double minc=INF; 36 int p=-1; 37 for(int j=1;j<=n;j++) 38 if(!vis[j]&&minc>lowc[j]) 39 { 40 minc=lowc[j]; 41 p=j; 42 } 43 if(minc != 0) 44 { 45 printf("%d %d ",pre[p],p); 46 } 47 if (p == -1) 48 return ; 49 vis[p]=true; 50 for(int j=1;j<=n;j++) 51 if(!vis[j]&&lowc[j]>cost[p][j]) 52 { 53 lowc[j]=cost[p][j]; 54 pre[j]=p; 55 } 56 } 57 return ; 58 } 59 60 int main() 61 { 62 63 //freopen("in.txt","r",stdin) ; 64 scanf("%d" , &n) ; 65 int i , j ; 66 for (i = 1 ; i <= n ; i++) 67 scanf("%d %d" , &p[i].x , &p[i].y) ; 68 for (i = 1 ; i <= n ; i++) 69 { 70 cost[i][i] = INF ; 71 for (j = i+1 ; j <= n ; j++) 72 { 73 double t = sqrt((double)(p[i].x - p[j].x) * (p[i].x - p[j].x) + (p[i].y - p[j].y) * (p[i].y - p[j].y)) ; 74 cost[i][j] = t ; 75 cost[j][i] = t ; 76 } 77 } 78 79 int m , u , v ; 80 scanf("%d" , &m) ; 81 while(m--) 82 { 83 scanf("%d %d" , &u , &v) ; 84 cost[u][v] = 0 ; 85 cost[v][u] = 0 ; 86 } 87 Prim() ; 88 89 90 return 0 ; 91 }