畜栏预定

#include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
using namespace std;
using PII=pair<int,int>;
const int N=5e4+10;
int n,id[N];
pair<PII,int >cows[N];
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>n;
	for(int i=0;i<n;++i){
		//get star and end time point
		cin>>cows[i].first.first>>cows[i].first.second;
		cows[i].second=i;
	}
	sort(cows,cows+n);
	priority_queue<PII,vector<PII>,greater<PII>> heap;
	for(int i=0;i<n;++i){
		if(heap.empty()||heap.top().first>=cows[i].first.first){
			PII stall={cows[i].first.second,heap.size()};
			id[cows[i].second]=stall.second;
			heap.push(stall);
		}else{
			auto stall=heap.top();
			heap.pop();
			stall.first=cows[i].first.second;
			id[cows[i].second]=stall.second;
			heap.push(stall);
		}
	}
	cout<<heap.size()<<'\n';
	for(int i=0;i<n;++i){
		cout<<id[i]+1<<'\n';
		
	}
	
	return 0;
}