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Cod sursa(job #950171)
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream f("rays.in"); ofstream g("rays.out");
typedef struct {long long x,y1,y2;} segment;
vector <segment> v,u;
int n,nr;
int cmp(segment a, segment b)
{ return (a.x*b.y2>b.x*a.y2);}
int main()
{ f>>n;
while(n--)
{ segment seg;
f>>seg.x>>seg.y1>>seg.y2;
if(seg.y1>seg.y2) swap(seg.y1,seg.y2);
if(seg.x>0) v.push_back(seg); else {seg.x=-seg.x; u.push_back(seg);}
}
sort(v.begin(),v.end(),cmp);
if(v.size())
{ ++nr;
for(int i=1; i<v.size(); ++i)
if(v[i-1].x*v[i].y1>v[i].x*v[i-1].y2) ++nr;
}
sort(u.begin(),u.end(),cmp);
if(u.size())
{ ++nr;
for(int i=1; i<u.size(); ++i)
if(u[i-1].x*u[i].y1>u[i].x*u[i-1].y2) ++nr;
}
g<<nr<<'\n'; g.close(); return 0;
}
/*
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
#define pb push_back
#define sz(c) int((c).size())
#define all(c) (c).begin(), (c).end()
typedef struct Segment {
int x, y1, y2;
} Segment;
int ret;
vector<Segment> v, u;
void ReadData() {
freopen("rays.in", "r", stdin);
freopen("rays.out", "w", stdout);
int N;
for (scanf("%d", &N); N; --N) {
Segment tmp;
scanf("%d %d %d", &tmp.x, &tmp.y1, &tmp.y2);
if (tmp.y1 > tmp.y2) tmp.y1 ^= tmp.y2 ^= tmp.y1 ^= tmp.y2;
if (tmp.x > 0) v.pb(tmp);
else {
tmp.x *= -1;
u.pb(tmp);
}
}
}
int cross(int X1, int Y1, int X2, int Y2) {
long long P = (long long)X1*Y2 - (long long)X2*Y1;
if (P == 0) return 0;
return P > 0 ? 1 : -1;
}
inline int cmp(Segment a, Segment b) {
return cross(a.x, a.y2, b.x, b.y2) == 1;
}
void Solve(vector<Segment> &v) {
sort(all(v), cmp);
if (!sz(v)) return;
int X = v[0].x;
int Y = v[0].y2;
++ret;
for (int i = 1; i < sz(v); ++i)
if (cross(X, Y, v[i].x, v[i].y1) == 1) {
++ret;
X = v[i].x;
Y = v[i].y2;
}
}
int main() {
ReadData();
Solve(v);
Solve(u);
printf("%d\n", ret);
}
*/