为什么我的代码会出现超时和运行时错误

#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<cmath>
using namespace std;
int n;
const int maxn=100001;
struct point{
    double x;
    double y;
}arr1[maxn];
vector<point> arr2;
bool cmp1(point a,point b){
    return a.x>b.x;
}
bool cmp2(point a,point b){
    return a.y>b.y;
}
double dis(point a,point b){
    double x=(a.x-b.x)*(a.x-b.x);
    double y=(a.y-b.y)*(a.y-b.y);
    double d=sqrt(x+y);
}
double solve(int left,int right){
    if(left==right){
        return 2e9;
    }
    if(left+1==right){
        return dis(arr1[left],arr1[right]);
    }
    int mid=(left+right)/2;
    double d1=solve(left,mid);
    double d2=solve((mid+1),right);
    double d=min(d1,d2);
    //cout<<"d1="<<d1<<endl;
    for(int i=0;i<n;i++){
        if(fabs(arr1[i].x-arr1[mid].x)<d){
            arr2.push_back(arr1[i]);
        }
    }
    int index=arr2.size();
    sort(arr2.begin(),arr2.end(),cmp2);
    for(int i=0;i<index;i++){//计算中间最短距离
        for(int j=i+1;j<index&&arr2[j].y-arr2[i].y<d;j++){
                double d3=dis(arr2[i],arr2[j]);
                if(d>d3){
                    d=d3;
                }
            }
        }
        return d;
    }
int main() {
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>arr1[i].x>>arr1[i].y;
    }
    sort(arr1,arr1+n,cmp1);
    double r=solve(0,n-1);
    printf("%.4f",r);
    return 0;
}