Submission #791583

#	Time	Username	Problem	Language	Result	Execution time	Memory
791583		peteza	Roads (CEOI20_roads)	C++14	15 / 100	35 ms	1500 KiB

roads

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

int n, xx1, yy1, xx2, yy2;
using pii = pair<int, int>;
struct line {
    pii a, b;
    line(int ax, int ay, int bx, int by){a={ax,ay};b={bx,by};}
    double gety() {
        if(a.first == b.first) return -a.first;
        return a.second - a.first*(1.00*b.second-a.second)/(b.first-a.first);
    }
};

vector<line> lns;

ostream& operator<<(ostream& os, pii a) {
    os << a.first << ' ' << a.second;
    return os;
}

int main() {
    cin >> n;
    for(int i=0;i<n;i++) {
        cin >> xx1 >> yy1 >> xx2 >> yy2;
        if(xx1 == xx2) {
            if(yy1 > yy2) swap(yy1, yy2);
        } else {
            if(xx1 > xx2) swap(xx1, xx2);
        }
        lns.emplace_back(xx1, yy1, xx2, yy2);
    }
    sort(lns.begin(), lns.end(), [](line a, line b){
        //if(a.a.first == 3 && a.a.second == 4 && b.a.first == 1 && b.a.second == 2) cout << a.gety() << ' ' << b.gety() << '\n';
        if(abs(a.gety()-b.gety())>=1e-6) return a.gety() > b.gety();
        return a.a < b.a;
    });
    for(int i=1;i<lns.size();i++) cout << lns[i-1].b << ' ' << lns[i].a << '\n';
}

Compilation message (stderr)

roads.cpp: In function 'int main()':
roads.cpp:38:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for(int i=1;i<lns.size();i++) cout << lns[i-1].b << ' ' << lns[i].a << '\n';
      |                 ~^~~~~~~~~~~

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