最小生成树Kruskal
原理参见上篇
1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 #include <algorithm> 5 #include <cmath> 6 using namespace std; 7 8 const int maxn=105; 9 10 int x[maxn],y[maxn]; 11 int v[maxn*maxn],u[maxn*maxn],w[maxn*maxn]; 12 int fa[maxn]; 13 int r[maxn*maxn]; 14 15 bool cmp (int x,int y){ 16 return w[x]<w[y]; 17 } 18 19 int find (int x){ 20 if (fa[x]==x) 21 return x; 22 return fa[x]=find (fa[x]); 23 } 24 25 int main (){ 26 int t; 27 //scanf ("%d",&t); 28 int n; 29 while (~scanf ("%d",&n)&&n){ 30 int m=n*(n-1)/2; 31 for (int i=0;i<m;i++){ 32 int a,b; 33 scanf ("%d%d%d%d",&v[i],&u[i],&a,&b); 34 if (b) 35 w[i]=0; 36 else w[i]=a; 37 } 38 for (int i=1;i<=n;i++) 39 fa[i]=i; 40 for (int i=0;i<m;i++) 41 r[i]=i; 42 int temp=0; 43 sort (r,r+m,cmp); 44 long long ans=0; 45 for (int i=0;i<m;i++){ 46 int fv=find(v[r[i]]); 47 int fu=find(u[r[i]]); 48 if (fv!=fu){ 49 ans+=w[r[i]]; 50 temp++; 51 fa[fv]=fu; 52 }//cout<<w[r[i]]<<" "; 53 } 54 //if (temp==n-1) 55 printf ("%I64d\n",ans); 56 } 57 return 0; 58 }
