HDU 1301 jungle roads

Minimum Spanning Tree prim

 

 

 1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 #include <algorithm> 5 #include <cmath> 6 using namespace std; 7  8 const int INF = 99999999 ; 9 const int maxn = 105 ;10 11 int map[maxn][maxn];12 int visit[maxn];13 int low[maxn];14 15 int main (){16     int n;17     while (~scanf ("%d",&n)&&n){18         for (int i=0;i<n;i++)19             for (int j=0;j<n;j++)20                 map[i][j]=INF;21         for (int i=0;i<n-1;i++){22             char c[10];23             int a,b;24             scanf ("%s%d",c,&a);25             while (a--){26                 scanf ("%s%d",c,&b);27                 map[i][(int)(c[0]-‘A‘)]=map[(int)(c[0]-‘A‘)][i]=b;28             }//cout<<n<<" "<<i<<endl;29         }30         memset (visit,0,sizeof visit);31         int ans=0;32         int mi;33         int pos=1;34         visit[1]=1;35         for (int i=0;i<n;i++)36             low[i]=map[pos][i];37         for (int i=0;i<n-1;i++){38             mi=INF;39             for (int j=0;j<n;j++)40                 if (!visit[j]&&low[j]<mi){41                     mi=low[j];pos=j;42                 }43             ans+=mi;visit[pos]=1;44             for (int j=0;j<n;j++)45                 if (!visit[j])46                     low[j]=min (low[j],map[pos][j]);47         }48         printf ("%d\n",ans);49     }50     return 0;51 }

 

HDU 1301 jungle roads