Submission #1014184

#	Time	Username	Problem	Language	Result	Execution time	Memory
1014184		hengliao	Tiles (BOI24_tiles)	C++17	0 / 100	73 ms	9684 KiB

Main

#include<bits/stdc++.h>
#include <chrono>
#include <random>
using namespace std;

#define F first
#define S second
#define pb push_back
#define vll vector<ll>
#define pll pair<ll, ll>
typedef long long ll;

ll n, m;

set<ll> lef;
set<ll> rig;
vector<pll> pts;
vector<pair<ll, pll>> seg;
vll con;
ll dumb;

bool inside(ll y){
    if(lef.upper_bound(y)==lef.begin()) return 0;
    auto it=prev(lef.upper_bound(y));
    auto it2=rig.lower_bound(y);
    if(it==lef.end() || it2==rig.end()){
        return 0;
    }
    ll f=*it;
    ll s=*it2;
    if(f<s){
        return 1;
    }
    return 0;
}

void solve(){
	cin>>n>>m;
    pts.resize(n);
    for(ll i=0;i<n;i++){
        cin>>pts[i].F>>pts[i].S;
        con.pb(pts[i].F);
    }
    for(ll i=0;i<n-1;i++){
        if(pts[i].F==pts[i+1].F){
            seg.pb({pts[i].F, {min(pts[i].S, pts[i+1].S), max(pts[i].S, pts[i+1].S)}});
        }
    }
    if(pts[n-1].F==pts[0].F){
        seg.pb({pts[0].F, {min(pts[0].S, pts[n-1].S), max(pts[0].S, pts[n-1].S)}});
    }
    sort(seg.begin(), seg.end());
    sort(con.begin(), con.end());
    con.erase(unique(con.begin(), con.end()), con.end());
    ll p=0;
    dumb=0;
    for(auto &x:con){
		bool done=0;
        while(p<n && seg[p].F<=x){
            //cout<<"______\n";
            //cout<<seg[p].F<<' '<<seg[p].S.F<<' '<<seg[p].S.S<<'\n';
            if(x==0){
                lef.insert(seg[p].S.F);
                rig.insert(seg[p].S.S);
                if((seg[p].S.S-seg[p].S.F)%2==1){
                    dumb--;
                }
            }
            else{
                if(inside(seg[p].S.F) && inside(seg[p].S.S)){
                    //cout<<"bruh\n";
                    ll orgl=*prev(lef.upper_bound(seg[p].S.F));
                    ll orgr=*rig.lower_bound(seg[p].S.S);
                    if((seg[p].S.F-orgl)%2==1){
                        dumb--;
                        rig.insert(seg[p].S.F);
                    }
                    else if(seg[p].S.F-orgl==0){
                        lef.erase(orgl);
                    }
                    else{
                        rig.insert(seg[p].S.F);
                    }
                    if((orgr-seg[p].S.S)%2==1){
                        dumb--;
                        lef.insert(seg[p].S.S);
                    }
                    else if(seg[p].S.S-orgr==0){
                        rig.erase(orgr);
                    }
                    else{
                        lef.insert(seg[p].S.S);
                    }
                }
                else{
                    if(inside(seg[p].S.F)){
                        //cout<<"damn\n";
                        rig.erase(seg[p].S.F);
                        rig.insert(seg[p].S.S);
                        ll orgl=*prev(lef.lower_bound(seg[p].S.F));
                        if((seg[p].S.S-orgl)%2==0 && (seg[p].S.F-orgl)%2==1){
                            dumb++;
                        }
                        else if((seg[p].S.S-orgl)%2==1 && (seg[p].S.F-orgl)%2==0){
                            dumb--;
                        }
                    }
                    else{
                        //cout<<"hi\n";
                        lef.erase(seg[p].S.S);
                        lef.insert(seg[p].S.F);
                        ll orgr=*rig.lower_bound(seg[p].S.S);
                        if((orgr-seg[p].S.F)%2==0 && (orgr-seg[p].S.S)%2==1){
                            dumb++;
                        }
                        else if((orgr-seg[p].S.F)%2==1 && (orgr-seg[p].S.S)%2==0){
                            dumb--;
                        }
                    }
                }
            }
			done=1;
            p++;
            /*cout<<x<<'\n';
            for(auto &it:lef){
                cout<<it<<' ';
            }
            cout<<'\n';
            for(auto &it:rig){
                cout<<it<<' ';
            }
            cout<<'\n';*/
        }
		if(x%2==1 && done){
			cout<<x-1<<'\n';
			return;
		}
        
        auto it=lef.begin();
        for(auto &r:rig){
            if((r-*it)%2==1){
                cout<<x<<'\n';
                return;
            }
            it=next(it);
        }
    }
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

	solve();
	return 0;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 9
• Subtask 3: 0 / 11
• Subtask 4: 0 / 19
• Subtask 5: 0 / 22
• Subtask 6: 0 / 25
• Subtask 7: 0 / 10