最小生成树模板——给出两点和权值 

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<map>
 5 #include<cmath>
 6 using namespace std;
 7 typedef long long ll;
 8 int fa[10010];
 9 int n, m;
10 struct edge {
11     int from;
12     int to;
13     ll cost;
14 }e[1000010];
15 struct node {
16     int x;
17     int y;
18 }island[10010];
19 void init()
20 {
21     for (int i = 1; i <= n; i++)
22     {
23         fa[i] = i;
24     }
25 }
26 int find(int x)
27 {
28     return x==fa[x] ? fa[x] : fa[x] = find(fa[x]);
29 }
30 void baba(int x, int y)
31 {
32     int fx = find(x);
33     int fy = find(y);
34     fa[fx] = fy;
35 }
36 bool same(int x, int y)
37 {
38     return find(x) == find(y);
39 }
40 
41 bool cmp(edge a, edge b)
42 {
43     return a.cost < b.cost;
44 }
45 void Kruskal()
46 {
47     sort(e + 1, e + m , cmp);
48     for (int i = 1; i < m; i++)
49     {
50         if (same(e[i].from, e[i].to))
51         {
52             continue;
53         }
54         baba(e[i].from, e[i].to);
55         printf("%d %d\n", e[i].from, e[i].to);
56     }
57 }
58 
59 int main()
60 {
61     scanf("%d", &n);
62     for (int i = 1; i <= n; i++)
63     {
64         scanf("%d%d", &island[i].x, &island[i].y);
65     }
66     init();
67     int M;
68     scanf("%d", &M);
69     for (int i = 1; i <= M; i++)
70     {
71         int a, b;
72         scanf("%d%d", &a, &b);
73         baba(a, b);
74     }
75     m = 1;
76     for (int i = 1; i <= n; i++)
77     {
78         for (int j = i + 1; j <= n; j++)
79         {
80             if (j == i)
81             {
82                 continue;
83             }
84             ll dis = (island[i].x - island[j].x)*(island[i].x - island[j].x) + (island[i].y - island[j].y)*(island[i].y - island[j].y);
85             e[m].cost = dis;
86             e[m].from = i;
87             e[m].to = j;
88             m++;
89         }
90     }
91     Kruskal();
92     return  0;
93 }

POJ 1751

posted @ 2019-04-17 21:00  Fzzf1  阅读(276)  评论(0)  编辑  收藏  举报