Floyd 遍历

注意由于可能在第n步后，所以必须枚3方的

#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<cctype>
#include<iostream>
#include<functional>
#include<algorithm>
using namespace std;
#define MAXN (2000+10)
#define MAXX (1000+10)
int n,x[MAXN],y[MAXN];
double dis(int i,int j)
{
	return sqrt(pow(abs(double(x[i]-x[j])),2)+pow(abs(double(y[i]-y[j])),2));
}
double d[MAXN][MAXN];
int main()
{
	int ii=1;
	while (1)
	{
		scanf("%d",&n);
		if (n==0) break;
		for (int i=1;i<=n;i++)
		{
			scanf("%d%d",&x[i],&y[i]);
		}



	//	for (int i=1;i<=n;i++) cout<<d[i]<<' ';
		for (int i=1;i<=n;i++)
		{
			for (int j=1;j<i;j++)
				d[i][j]=d[j][i]=dis(i,j);
		}
		for (int k=1;k<=n;k++)
			for (int i=1;i<=n;i++)
				for (int j=1;j<=n;j++)
					d[i][j]=min(d[i][j],max(d[i][k],d[k][j]));





		printf("Scenario #%dn",ii);
		printf("Frog Distance = %.3lfnn",d[1][2]);
//		cout<<d[1];



		ii++;
	}
	return 0;
}