kruskal实现~~
1 #include<iostream> 2 #include<cmath> 3 #include<algorithm> 4 #include<cstdio> 5 using namespace std; 6 #define maxn 300 7 int par[maxn]; 8 int pos; 9 int n,cnt; 10 double len; 11 struct node 12 { 13 int x; 14 int y; 15 double w;//!!!可以不开方 16 }; 17 node e[maxn * (maxn - 1) / 2]; 18 int cmp(const node &a , const node &b) 19 { 20 return a.w < b.w; 21 }; 22 struct p 23 { 24 int x; 25 int y; 26 }po[maxn]; 27 void init() 28 { 29 for(int i = 1; i <= n+5; i++) 30 par[i] = i; 31 pos = 0; 32 len = 0.0; 33 cnt = 0; 34 } 35 int Find(int x) 36 { 37 int k,j,r; 38 r = x; 39 while(par[r] != r) 40 r = par[r]; 41 k = x; 42 while(k != r) 43 { 44 j = par[k]; 45 par[k] = r; 46 k = j; 47 } 48 return r; 49 } 50 int Merge(int x,int y) 51 { 52 int a = Find(x); 53 int b = Find(y); 54 if(a != b) 55 { 56 par[a] = par[b]; 57 return 1; 58 } 59 return 0; 60 } 61 void input() 62 { 63 int u,v; 64 for(int i = 1; i <= n; i++) 65 scanf("%d%d",&po[i].x,&po[i].y); 66 } 67 68 void make() 69 { 70 double dist; 71 for(int i = 1; i <= n; i++) 72 { 73 for(int j = i + 1; j <= n; j++) 74 { 75 dist = (po[i].x - po[j].x) * (po[i].x - po[j].x) + (po[i].y - po[j].y) * (po[i].y - po[j].y); 76 if(dist >= 100 && dist <= 1000000) 77 { 78 e[pos].x = i; 79 e[pos].y = j; 80 e[pos].w = sqrt(dist); 81 pos++; 82 } 83 } 84 } 85 sort(e,e+pos,cmp); 86 for(int i = 0; i < pos; i++) 87 { 88 if(Merge(e[i].x,e[i].y)) 89 { 90 Merge(e[i].x,e[i].y); 91 len += e[i].w; 92 cnt++; 93 } 94 } 95 } 96 int main() 97 { 98 freopen("input.txt","r",stdin); 99 int t; 100 scanf("%d",&t); 101 while(t--) 102 { 103 scanf("%d",&n); 104 init(); 105 input(); 106 make(); 107 if(cnt < n - 1) printf("oh! "); 108 else printf("%.1lf ",len * 100); 109 } 110 111 return 0; 112 }