题解

代码如下、

#include<bits/stdc++.h>
using namespace std;
int n;
struct node{
double x,y;
}a[200005];
double cnt(double x,double y,double xx,double yy){
    return sqrt(abs(x-xx)*abs(x-xx)+abs(y-yy)*abs(y-yy));
}
bool cmp(node aa,node bb){
    if(aa.x!=bb.x)return aa.x<=bb.x;
    else return aa.y<=bb.y;
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i].x>>a[i].y;
    }
    sort(a+1,a+1+n,cmp);
    double mn=1e18;
    for(int i=1;i<n-1;i++){
        mn=min(mn,cnt(a[i].x,a[i].y,a[i+1].x,a[i+1].y));
        mn=min(mn,cnt(a[i].x,a[i].y,a[i+2].x,a[i+2].y));
    }
    printf("%.4f",mn);
    return 0;
}