题解 | 线段重合

#include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
using namespace std;

int n, ans;
vector<pair<int, int>> a;
priority_queue<int, vector<int>, greater<int>> pq;

int main()
{
    cin >> n;
    for(int i = 0, l, r; i < n; i++)
    {
        cin >> l >> r;
        a.push_back({l, r});
    }
    sort(a.begin(), a.end(), [](auto& a1, auto& a2) { return a1.first < a2.first; });

    for(int i = 0; i < n; i++)
    {
        while(!pq.empty() && pq.top() <= a[i].first) pq.pop();
        pq.push(a[i].second);
        int len = pq.size();
        ans = max(ans, len);
    }

    cout << ans;

    return 0;
}