kruskal实现
1 #include<iostream> 2 #include<cmath> 3 #include<algorithm> 4 #include<cstdio> 5 using namespace std; 6 #define maxn 760 7 int par[maxn]; 8 int pos; 9 int n,m; 10 struct node 11 { 12 int x; 13 int y; 14 double w;//!可以不开方比较 15 }; 16 node e[maxn * (maxn - 1) / 2]; 17 int cmp(const node &a , const node &b) 18 { 19 return a.w < b.w; 20 }; 21 struct p 22 { 23 int x; 24 int y; 25 }po[maxn]; 26 void init() 27 { 28 for(int i = 1; i <= n+5; i++) 29 par[i] = i; 30 pos = 0; 31 } 32 int Find(int x) 33 { 34 int k,j,r; 35 r = x; 36 while(par[r] != r) 37 r = par[r]; 38 k = x; 39 while(k != r) 40 { 41 j = par[k]; 42 par[k] = r; 43 k = j; 44 } 45 return r; 46 } 47 void Merge(int x,int y) 48 { 49 int a = Find(x); 50 int b = Find(y); 51 if(a != b) 52 { 53 par[a] = par[b]; 54 } 55 } 56 void input() 57 { 58 int u,v; 59 for(int i = 1; i <= n; i++) 60 cin>>po[i].x>>po[i].y; 61 cin>>m; 62 while(m--) 63 { 64 cin>>u>>v; 65 Merge(u,v); 66 } 67 } 68 69 void make() 70 { 71 for(int i = 1; i <= n; i++) 72 { 73 for(int j = i + 1; j <= n; j++) 74 { 75 if(Find(i) != Find(j)) 76 { 77 e[pos].x = i; 78 e[pos].y = j; 79 e[pos].w = (po[i].x - po[j].x) * (po[i].x - po[j].x) + (po[i].y - po[j].y) * (po[i].y - po[j].y); 80 pos++; 81 } 82 } 83 } 84 sort(e,e+pos,cmp); 85 for(int i = 0; i < pos; i++) 86 { 87 if(Find(e[i].x) != Find(e[i].y)) 88 { 89 Merge(e[i].x,e[i].y); 90 cout<<e[i].x<<" "<<e[i].y<<endl; 91 } 92 } 93 } 94 int main() 95 { 96 freopen("input.txt","r",stdin); 97 int t; 98 cin>>t; 99 while(t--) 100 { 101 cin>>n; 102 init(); 103 input(); 104 make(); 105 if(t!=0)cout<<endl; //There is a blank line between output blocks.except the last one 106 } 107 108 return 0; 109 }