畜栏预定

 

#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> PII;
const int N = 50010;
pair<PII, int> cows[N];
//首先存储开始时间和结束时间，然后存储编号id
int id[N]; //存储n头牛依次放在哪个畜栏
int main() {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> cows[i].first.first >> cows[i].first.second;
        cows[i].second = i;
    }
    sort(cows, cows + n); //从小到大排序
    priority_queue<PII, vector<PII>, greater<PII> > heap;
    for (int i = 0; i < n; i++) { 
        PII cow = cows[i].first;
        if (heap.empty() || heap.top().first >= cow.first) {
            PII stall = {cow.second, heap.size() + 1}; //新增一个畜栏
            //first是终止时间，second是编号，注意是从1开始
            id[cows[i].second] = stall.second;
            heap.push(stall);
        } else {
            //否则，放入最早结束的那个畜栏
            PII stall = heap.top();
            heap.pop();
            stall.first = cow.second;
            id[cows[i].second] = stall.second;
            heap.push(stall);
        }
    }
    cout << heap.size() << endl;
    for (int i = 0; i < n; i++) {
        cout << id[i] << endl;
    }
    return 0;
}