题意：求任意两点之间的距离的最少一个距离

思路：枚举一下就可以了

#include <iostream>

#include<cstdio>

#include<cmath>

using namespace std;

#define N 10010

struct node{

	double x,y;

}p[N];

int main(int argc, char** argv) {

	int n,i,j;

	double mdist,tmp;

	while(scanf("%d",&n)&&n){

		for(i=0;i<n;i++){

			scanf("%lf%lf",&p[i].x,&p[i].y);

		}

		mdist=0xfffffff;

		for(i=0;i<n;i++){

			for(j=i+1;j<n;j++){

				tmp=(p[i].x-p[j].x)*(p[i].x-p[j].x)+(p[i].y-p[j].y)*(p[i].y-p[j].y);

				mdist=min(mdist,tmp);

			}

		}

		mdist=sqrt(mdist);

		if(mdist>=10000)

			printf("INFINITY\n");

		else

			printf("%.4lf\n",mdist);

	}

	return 0;

}