最小生成树_prim

<pre name="code" class="cpp"><pre name="code" class="cpp">#include<cstdio>#include<iostream>#define inf 88888888using namespace std;int map[500][500],path[505];int n;void prim(int x){    int dis[101],i,j,k,minn;    for(i=1;i<=n;i++)    {dis[i]=map[i][x];path[i]=x;}    for(i=1;i<=n-1;i++)    {    minn=inf;    for(j=1;j<=n;j++)    if((dis[j]!=0)&&(dis[j]<minn))        {minn=dis[j];k=j;};        dis[k]=0;        for(j=1;j<=n;j++)        if(dis[j]>map[j][k])        {dis[j]=map[j][k];path[j]=k;}    }}int main(){int i,j,x,y,len,tot=0,m;char ch;cin>>n;for(i=1;i<=n;i++)//初始化 for(j=1;j<=n;j++)if(i!=j)map[i][j]=inf;for(i=1;i<=n-1;i++)//init{cin>>ch;scanf("%d",&m);x=int(ch)-int('A')+1;for(j=1;j<=m;j++){cin>>ch;scanf("%d",&len);y=int(ch)-int('A')+1;map[x][y]=len;map[y][x]=len;}}prim(1);for(i=1;i<=n;i++){if(path[i]!=i){tot=tot+map[i][path[i]];}}cout<<tot;}