Submission #624487

#	Time	Username	Problem	Language	Result	Execution time	Memory
624487		Vladth11	Roads (CEOI20_roads)	C++14	0 / 100	1 ms	212 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 = 100001;
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
    }
};
 
struct segment {
    int a, b, c, d;
    int idx;
} sgt[NMAX];
 
vector <event> events;
map <pii, pii> mp;
set <pii> already;
 
bool signs(int a, int b) {
    if(a < b)
        swap(a, b);
    if(a > 0 && b < 0)
        return 0;
    return 1;
}
 
int cnt = 0;
 
void adauga(int a, int b) {
    if(a < b)
        swap(a, b);
    cnt++;
    if(already.find({a, b}) != already.end()) return;
    already.insert({a, b});
    segment first = sgt[a];
    segment second = sgt[b];
    if(first.b < second.b) {
        swap(first, second);
    } else if(first.b == second.b) {
        if(first.a < second.a) {
            swap(first, second);
        }
    }
    if(first.a >= second.c) {
        cout << first.a << " " << first.b << " " << second.c << " " << second.d << "\n";
        return;
    }
    if(second.a >= first.c){
        cout << first.c << " " << first.d << " " << second.a << " " << second.b << "\n";
        return;
    }
    cout << first.a << " " << first.b << " " << second.a << " " << second.b << "\n";
}
 
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++) {
        int 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 <pii> active;
    vector <pair <pii, int> > facut;
    for(int i = 0; i < events.size(); i++) {
        if(events[i].stare > 0) {
            active.insert({events[i].x.second, events[i].stare});
            if(events[i].x.first != -INF)
                facut.push_back({events[i].x, events[i].stare});
        } else {
            if(-events[i].stare < n - 1) {
                auto sus = active.upper_bound({events[i].x.second, -1});
                if(sus == active.begin()){
                    debug("Da");
                    exit(0);
                }
                sus = prev(sus);
                auto jos = active.lower_bound({events[i].x.second + 1, -1});
                int indS = (*sus).second;
                int 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});
        }
        if(i == events.size() || (events[i + 1].x.first != events[i].x.first || !signs(events[i + 1].stare, events[i].stare))) {
            for(auto x : facut) {
                auto sus = active.upper_bound({x.first.second, -1});
                sus = prev(sus);
                auto jos = active.lower_bound({x.first.second + 1, -1});
                int indS = (*sus).second;
                int indJ = (*jos).second;
                if(mp.find({indS, indJ}) == mp.end()) {
                    if(sgt[indS].a != -INF) {
                        adauga(indS, x.second);
                    } else if(sgt[indJ].a != -INF) {
                        adauga(indJ, x.second);
                    }
                } else {
                    pii conectare = mp[ {indS, indJ}];
                    adauga(conectare.second, 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};
            }
            facut.clear();
        }
    }
    assert(cnt == n - 3);
    return 0;
 
}

Compilation message (stderr)

roads.cpp: In function 'int main()':
roads.cpp:113:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<event>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |     for(int i = 0; i < events.size(); i++) {
      |                    ~~^~~~~~~~~~~~~~~
roads.cpp:136:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<event>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  136 |         if(i == events.size() || (events[i + 1].x.first != events[i].x.first || !signs(events[i + 1].stare, events[i].stare))) {
      |            ~~^~~~~~~~~~~~~~~~

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