题解 | 植树节

#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
    ll n;
    cin >> n;
    vector<ll> diff(1000000,0);
    ll l,r;
    for(int i=0; i<n; i++){
        cin >> l >> r;
        diff[l] +=1;
        diff[r+1] -= 1;
    }
    vector<ll> ans(1000000);
    ans[0] = diff[0];
    ll max = ans[0];
    for(int i=1; i<1000000; i++){
        ans[i] = ans[i-1]+diff[i];
        if(ans[i] > max) max = ans[i];
    }
    cout << max;
}