求最近的点对，有问题求助大佬们

#include<bits/stdc++.h>
using namespace std;
struct dian{
	int x,y;
}; 
int main(){
	int num;
	cin>>num;
	dian d[num];
	float mi=100;//最近距离
	float dis;//两点间距离
	int n,m;
	for(int i=0;i<num;i++){
		cin>>d[i].x>>d[i].y;
	}
	for(int i=0;i<num;i++){
		for(int j=i+1;j<num;j++){
			dis=sqrt(pow((d[i].x-d[j].x),2)+pow((d[i].y-d[j].y),2));
			if(dis<=mi){
				mi=dis;
				n=i;
				m=j;}
			
		}
	}
	cout<<d[n].x<<" "<<d[n].y<<" "<<d[m].x<<" "<<d[m].y<<" "<<endl;
	cout<<dis<<endl;
	return 0;
}