Submission #624677

#	Time	Username	Problem	Language	Result	Execution time	Memory
624677		Vladth11	Roads (CEOI20_roads)	C++14	30 / 100	697 ms	51656 KiB

roads

#include <bits/stdc++.h>
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "

using namespace std;
typedef long long ll;
typedef pair <long double, long double> pii;

const ll NMAX =200001;
const ll VMAX = 101;
const ll INF = 1e9;
const ll MOD = 1000000007;
const ll BLOCK = 447;
const ll base = 117;
const ll nr_of_bits = 18;
const ll inv2 = 500000004;

set <pii> exista;

struct event {
    pii x;
    int stare;
    bool operator < (const event a) {
        if(a.x.first != x.first) {
            return x.first < a.x.first;
        }
        if(a.stare != stare) {
            return stare > a.stare;
        }
        return x.second < a.x.second; /// Nu ar trb sa aiba importanta, dar e necesar sa nu busesc sortarea
    }
};

long double swipex;

struct segment {
    long double a, b, c, d;
    long double idx;
    long double gety() {
        if(c != a)
            return (long double)b + (long double)(swipex - a) * (long double)(d - b) / (long double)(c - a);
        else
            return (long double)b;
    }
} sgt[NMAX];

vector <event> events;
map <pii, pii> mp;
set <pii> already;

bool signs(long double a, long double b) {
    if(a < b)
        swap(a, b);
    if(a > 0 && b < 0)
        return 0;
    return 1;
}

long double cnt = 0;

void adauga(int a, int b) {
    if(a < b)
        swap(a, b);
    cnt++;
    segment first = sgt[a];
    segment second = sgt[b];
    if(first.a < second.a) {
        swap(first, second);
    } else if(first.a == second.a) {
        if(first.b < second.b) {
            swap(first, second);
        }
    } if(first.a >= second.c) {
        cout << (int)first.a << " " << (int)first.b << " " << (int)second.c << " " << (int)second.d << "\n";
        return;
    }
    if(second.a >= first.c) {
        cout <<(int)first.c << " " << (int)first.d << " " << (int)second.a << " " << (int)second.b << "\n";
        return;
    }
    cout << (int)first.a << " " << (int)first.b << " " << (int)second.a << " " << (int)second.b << "\n";
}

struct ura {
    long double first;
    int second;
    bool operator < (const ura a)const {
        if(a.second == -1 && second == -1) {
            return first < a.first;
        }
        if(a.second == -1) {
            return sgt[second].gety() < a.first;
        }
        if(second == -1) {
            return first < sgt[a.second].gety();
        }
        return sgt[second].gety() < sgt[a.second].gety();
    }
};

int main() {
    //ifstream cin(".out");
    //ofstream cout(".out");
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, i;
    cin >> n;
    for(i = 1; i <= n; i++) {
        long double a, b, c, d;
        cin >> a >> b >> c >> d;
        if(a > c) {
            swap(b, d);
            swap(a, c);
        } else if(a == c) {
            if(b > d)
                swap(b, d); /// nu stiu daca e nevoie
        }
        sgt[i] = {a, b, c, d, i};
        exista.insert({a, b});
        exista.insert({c, d});
        events.push_back({{a, b}, i});
        events.push_back({{c, d}, -i});
    }
    n += 2;
    sgt[n - 1] = {-INF, -INF, INF, -INF, n - 1};
    events.push_back({{-INF, -INF}, n - 1});
    events.push_back({{INF, -INF}, -(n - 1)});
    sgt[n] = {-INF, INF, INF, INF, n};
    events.push_back({{-INF, INF}, n});
    events.push_back({{INF, INF}, -n});
    sort(events.begin(), events.end());
    set <ura> active;
    for(long double i = 0; i < events.size(); i++) {
        swipex = events[i].x.first;
        if(events[i].stare > 0) {
            active.insert({events[i].x.second, events[i].stare});
        } else {
            if(-events[i].stare < n - 1) {
                auto sus = active.lower_bound({sgt[-events[i].stare].gety(), -1});
                sus = prev(sus);
                auto jos = active.lower_bound({sgt[-events[i].stare].gety(), -1});
                jos = next(jos);
                long double indS = (*sus).second;
                long double indJ = (*jos).second;
                if(mp.find({indS, indJ}) != mp.end())
                    mp[ {indS, indJ}] = max(mp[ {indS, indJ}], {events[i].x.first, -events[i].stare});
                else
                    mp[ {indS, indJ}] = {events[i].x.first, -events[i].stare};
            }
            active.erase({events[i].x.second, -events[i].stare});
            continue;
        }
        if(events[i].stare > n - 2) continue;
        pair <pii, int> x = {events[i].x, events[i].stare};
        auto sus = active.lower_bound({x.first.second, -1});
        sus = prev(sus);
        auto jos = active.lower_bound({x.first.second, -1}); /// nu vrem daca trece chiar la limita sa-l ignor
        jos = next(jos);
        int indS = (*sus).second;
        int indJ = (*jos).second;
        if(mp.find({indS, indJ}) == mp.end()) {
            pii maxim = max((pii){sgt[indS].a, indS}, (pii){sgt[indJ].a, indJ});
            if(sgt[indS].c <= x.first.first){
                maxim = max(maxim, {sgt[indS].c, indS});
            }
            if(sgt[indJ].c <= x.first.first){
                maxim = max(maxim, {sgt[indJ].c, indJ});
            }
            if(maxim.second == indS && indS < n - 1)
                adauga(indS, x.second);
            else if(maxim.second == indJ && indJ < n - 1)
                adauga(indJ, x.second);
        } else {
            pii conectare = mp[ {indS, indJ}];
            pii maxim = max({conectare, {sgt[indS].a, indS}, {sgt[indJ].a, indJ}});
            if(sgt[indS].c <= x.first.first){
                maxim = max(maxim, {sgt[indS].c, indS});
            }
            if(sgt[indJ].c <= x.first.first){
                maxim = max(maxim, {sgt[indJ].c, indJ});
            }
            if(maxim == conectare)
                adauga(conectare.second, x.second);
            else if(maxim.second == indS)
                adauga(indS, x.second);
            else if(maxim.second == indJ)
                adauga(indJ, x.second);
        }
        if(mp.find({indS, indJ}) != mp.end())
            mp[ {indS, indJ}] = max(mp[ {indS, indJ}], {x.first.first, x.second});
        else
            mp[ {indS, indJ}] = {x.first.first, x.second};
    }
    assert(cnt == n - 3);
    return 0;

}

Compilation message (stderr)

roads.cpp: In function 'int main()':
roads.cpp:119:31: warning: narrowing conversion of 'i' from 'int' to 'long double' [-Wnarrowing]
  119 |         sgt[i] = {a, b, c, d, i};
      |                               ^
roads.cpp:126:44: warning: narrowing conversion of '(n - 1)' from 'int' to 'long double' [-Wnarrowing]
  126 |     sgt[n - 1] = {-INF, -INF, INF, -INF, n - 1};
      |                                          ~~^~~
roads.cpp:129:36: warning: narrowing conversion of 'n' from 'int' to 'long double' [-Wnarrowing]
  129 |     sgt[n] = {-INF, INF, INF, INF, n};
      |                                    ^

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