Submission #588587

#	Time	Username	Problem	Language	Result	Execution time	Memory
588587		jiahng	Roads (CEOI20_roads)	C++14	100 / 100	206 ms	16156 KiB

roads

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

typedef long long ll;
#define int ll
typedef pair<int32_t, int32_t> pi;
typedef vector <int> vi;
typedef vector <pi> vpi;
typedef pair<pi, ll> pii;
typedef set <ll> si;
typedef long double ld;
#define f first
#define s second
#define mp make_pair
#define FOR(i,s,e) for(int i=s;i<=int(e);++i)
#define DEC(i,s,e) for(int i=s;i>=int(e);--i)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lbd(x, y) lower_bound(all(x), y)
#define ubd(x, y) upper_bound(all(x), y)
#define aFOR(i,x) for (auto i: x)
#define mem(x,i) memset(x,i,sizeof x)
#define fast ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define maxn 400010
#define INF (ll)(1e9+10)
#define MOD 1000000007
typedef pair <vi, int> pvi;
typedef pair <int,pi> ipi;
typedef vector <pii> vpii;
typedef pair <pi,pi> pipi;

int N;
pi l, r;

ld isect(pipi line, int x){
	if (line.s.f == line.f.f) return line.f.s;
	ld m = ld(line.s.s - line.f.s) / ld(line.s.f - line.f.f);
	return m * ld(x - line.f.f) + line.f.s;
}
vector <pipi> v;
struct cmp{
	bool operator()(ipi x, ipi y){
		int i = x.f, j = y.f;
		return isect(v[i], max(v[i].f.f, v[j].f.f)) < isect(v[j], max(v[i].f.f, v[j].f.f));
	}
};	

struct DS : set <ipi, cmp> { // (index, rmost)

	
	void add(int x){
		//~ cout << "ADD " << x << '\n';
		iterator z;
		if (v[x].f.f == v[x].s.f) z = insert(ipi(x, v[x].s)).f;
		else z = insert(ipi(x, v[x].f)).f;
		if (z != begin()){
			--z;
			ipi n = ipi(z->f, max(z->s, v[x].f));
			if (v[x].f.f == v[x].s.f) n.s = max(n.s, v[x].s);
			erase(z);
			insert(n);
		}
	}
	
	void remove(int x){
		//~ cout << "REMOVE " << x << '\n';
		iterator z = --upper_bound(ipi(x, pi(-1,-1)));
		pi rmost = z->s;
		assert(z != end());
		z = erase(z);
		if (z != begin()){
			z--;
			ipi n = ipi(z->f, max({z->s, rmost, v[x].s}));
			erase(z);
			insert(n);
		}
	}
	
	ipi qry(int x){
		auto z = lower_bound(ipi(x, v[x].f));
		//~ if (z == begin()){
			//~ cout << "BAD " << z->f << ' ' << z->s.f << ' ' << z->s.s << '\n';
			//~ exit(0);
		//~ }
		assert(z != begin());
		return *(--z);
	}
};

int32_t main(){
    fast;
    cin >> N;
    FOR(i,1,N){
        cin >> l.f >> l.s >> r.f >> r.s;
        if (l > r) swap(l, r);
        v.pb(pipi(l, r));
    }
    v.pb(pipi(pi(-INF, -INF), pi(INF, -INF)));
    sort(all(v));
    
    vector <pii> v2;
    FOR(i,1,v.size()-1){
		v2.pb(pii(pi(v[i].f.f, i), 1));
		v2.pb(pii(pi(v[i].s.f, i), 0));
	}
	sort(all(v2), [](pii i,pii j){
		if (i.f.f != j.f.f) return i.f.f < j.f.f;
		if (i.s != j.s) return i.s > j.s;
		return i.f.s < j.f.s;
	});
	//~ cout << isect(v[1], v[1].f.f);
	//~ FOR(i,1,v.size()-1){
		//~ if (!cmp()(ipi(0, pi(-1,-1)), ipi(i, pi(-1,-1)))){
			//~ cout << isect(v[0], v[i].f.f) << ' ' << isect(v[i], v[i].f.f) << '\n';
		//~ }
	//~ }
    //~ return 0;
    DS st; st.add(0);
    //~ pi x = st.qry(1);
    //~ cout << v[0].f.f << ' ' << v[0].f.s << '\n';
    //~ return 0;
    vector <pipi> ans;
    aFOR(i, v2){
		int x = i.f.s;
		if (i.s == 1){
			//~ if (x == (int)v.size()-1) cout << st.qry(x).f << '\n';
			pi rmost = st.qry(x).s;
			if (rmost.f != -INF) ans.pb(pipi(v[x].f, rmost));
			st.add(x);
		}else st.remove(x);
	}

    
    aFOR(i,ans){
        cout << i.f.f << ' ' << i.f.s << ' ' << i.s.f << ' ' << i.s.s << '\n';
    }
}

• Subtask 1: 0 / 0
• Subtask 2: 15 / 15
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 40 / 40