Submission #833305

#	Time	Username	Problem	Language	Result	Execution time	Memory
833305		vjudge1	Exam (eJOI20_exam)	C++17	0 / 100	3 ms	788 KiB

exam

#include<bits/stdc++.h>
#define ll long long
#define endl "\n"
#define fi first
#define se second
#define pb push_back
#define pll pair<long long, long long>
#define loop(i,n) for(int i=1;i<=n;i++)
#define loop0(i,n) for(int i=0;i<n;i++)
using namespace std;

//pbds template
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

void solve(){
	ll n;
	cin >> n;
	ll a[n+5] = {0};
	ll b[n+5] = {0};
	vector<pair<pair<ll,ll>,ll>> v;
	map<ll,vector<ll>> m;
	for(int i=1;i<=n;i++){
		cin >> a[i];
	}
	for(int i=1;i<=n;i++){
		cin >> b[i];
	}
	ll ans = 0;
	for(int i=1;i<=n;i++){
		v.pb({{a[i],b[i]},i});
	}
	sort(v.begin(),v.end());
	ordered_set<ll> o_set;
	for(auto i:v){
//		cout << i.fi.fi << ' ' << i.fi.se << ' ' << ans << endl;
//		cout << "o_set : ";
		for(auto j:o_set){
//			cout << "DEBUG" << endl;
//			cout << j << ' ';
		}
//		cout << endl;
		if(m.count(i.fi.fi)){
			ll cnt = 1;
			ll mx = 0;
			ll idx = 0;
			ll start = 0;
			ll end = 0;
			for(auto j:m[i.fi.fi]){
				ll idx1 = o_set.order_of_key(i.se);
				ll idx2 = o_set.order_of_key(j);
				ll sel = abs(idx1-idx2);
//				cout << idx1 << ' ' << idx2 << ' ' << cnt << endl;
				if(cnt-sel>mx){
					idx = cnt;
					mx = cnt-sel;
					start = min(i.se,j);
					end = max(i.se,j);
				}
				cnt++;
			}
//			cout << "mx : " << mx << endl;
			if(mx>0){
				ordered_set<ll> o_set2;
				ans += mx;
				for(auto i:o_set){
					if(i<start||i>end){
						o_set2.insert(i);
					}
				}
				for(int j=0;j<idx;j++){
//					cout << m[i.fi.fi][j] << endl;
					o_set2.insert(m[i.fi.fi][j]);
				}
				o_set = o_set2;
//				cout << o_set.size() << endl;
			}
		}
		if(i.fi.fi==i.fi.se){
			ans++;
			o_set.insert(i.se);
		}
		else{
			m[i.fi.se].pb(i.se);
		}
	}
	cout << o_set.size() << endl;
//	for(auto i:o_set){
//		cout << i << ' ';
//	}
//	cout << endl;
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int tc = 1;
//	cin >> tc;
	while(tc--){
	   solve();
	}
}

Compilation message (stderr)

exam.cpp: In function 'void solve()':
exam.cpp:42:12: warning: unused variable 'j' [-Wunused-variable]
   42 |   for(auto j:o_set){
      |            ^

• Subtask 1: 0 / 14
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22