> #include <cstdio>
> #include <cmath>
> 
> const int maxn=110,maxm=60,oo=2134000000;
> 
> int n,s[maxn];
> int x[maxn][maxm],y[maxn][maxm];
> long double dp[maxn][maxm];
> 
> long double Distance(int x1,int y1,int x2,int y2)
> {
> 	return sqrt( (x1-x2) * (x1-x2)+(y1-y2) * (y1-y2) );
> }
> int main()
> {
> 	freopen("p2173.in","r",stdin);
> 	freopen("p2173.out","w",stdout);
> 	
> 	scanf("%d",&n);
> 	for (int i=2;i<=n;i++)
> 	for (int j=1;j<=maxm;j++)
> 	dp[i][j]=oo;
> 	for (int i=1;i<=n;i++)
> 	{
> 		scanf("%d",&s[i]);
> 		for (int j=1;j<=s[i];j++)
> 		scanf("%d%d",&x[i][j],&y[i][j]);
> 	}
> 	for (int i=2;i<=n;i++)
> 	{
> 		for (int j=1;j<=s[i];j++)
> 		for (int k=1;k<=s[i-1];k++)
> 		if (dp[i-1][k]+Distance(x[i-1][k],y[i-1][k],x[i][j],y[i][j])<dp[i][j])
> 		dp[i][j]=dp[i-1][k]+Distance(x[i-1][k],y[i-1][k],x[i][j],y[i][j]);
> 	}
> 	long double min=oo;
> 	for (int i=1;i<=s[1];i++)
> 	for (int j=1;j<=s[n];j++)
> 	if (dp[n][j]+Distance(x[1][i],y[1][i],x[n][j],y[n][j])<min)
> 	min=dp[n][j]+Distance(x[1][i],y[1][i],x[n][j],y[n][j]);
> 	min=min * 100;
> 	int ans=int(min);
> 	printf("%d\n",ans);
> 	return 0;
> }
我知道了，没有枚举牛1的位置。千万要注意啊！！！！！！！！！