USACO Section 3.1 Agri-Net - [水]最小生成数模板题

赤果果的最小生成树...于是就用Prim水了...

Program:

/* ID: zzyzzy12 LANG: C++ TASK: agrinet */ #include<iostream> #include<istream> #include<stdio.h> #include<string.h> #include<math.h> #include<stack> #include<algorithm> #include<queue> #define oo 2000000000 #define ll long long using namespace std; int n,arc[105][105]; int Prim() { bool used[105]; int i,k,j,m,p,ans=0; memset(used,false,sizeof(used)); used[1]=1; for (k=1;k<n;k++) { m=100000; for (i=1;i<=n;i++) for (j=1;j<=n;j++) if (used[i] && !used[j] && m>arc[i][j]) { m=arc[i][j]; p=j; } used[p]=true; ans+=m; } return ans; } int main() { freopen("agrinet.in","r",stdin); freopen("agrinet.out","w",stdout); scanf("%d",&n); for (int i=1;i<=n;i++) for (int j=1;j<=n;j++) scanf("%d",&arc[i][j]); printf("%d\n",Prim()); return 0; }