题解：AT_abc401_g [ABC401G] Push Simultaneously

#include <bits/stdc++.h>
using namespace std;
int n,top,c[3001],d[3001];
long long s1[301],s2[301],s3[301],s4[301];
vector<pair<long double,pair<int,int>>>a;
vector<int>b[3001];
bool dfs(int x){
	d[x]=1;
	for(auto j:b[x]){
		if(!c[j]||(!d[c[j]]&&dfs(c[j]))){
			c[j]=x;
			return 1;
		}
	}
	return 0;
}
bool ok(long long x){
	for(int i=1;i<=2*n;i++){
		c[i]=0,b[i].clear();
	}
	for(auto i:a){
		if(!x){
			break;
		}
		x--;
		b[i.second.first].push_back(i.second.second);
		b[i.second.second].push_back(i.second.first);
	}
	int ans=0;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=2*n;j++){
			d[j]=0;
		}
		if(dfs(i)){
			ans++;
		}
	}
	if(ans==n){
		return 1;
	}
	return 0;
}
int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%lld%lld",&s1[i],&s2[i]);
	}
	for(int i=1;i<=n;i++){
		scanf("%lld%lld",&s3[i],&s4[i]);
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			top++;
			a.push_back({sqrt((__int128)abs(s1[i]-s3[j])*abs(s1[i]-s3[j])+(__int128)abs(s2[i]-s4[j])*abs(s2[i]-s4[j])),{i,n+j}});
		}
	}
	sort(a.begin(),a.end());
	long long l=0,r=top+1;
	for(;l+1<r;){
		long long x=(l+r)/2;
		if(ok(x)){
			r=x;
		}
		else{
			l=x;
		}
	}
	printf("%.20Lf",a[r-1].first);
}
```c