Cod sursa(job #2207510)

Utilizator Ruxandra985Nanu Ruxandra Laura Ruxandra985 Data 25 mai 2018 20:40:15
Problema Rays Scor 70
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.52 kb
#include <cstdio>
#include <algorithm>

using namespace std;
struct segm{
    long long a;
    long long o;
    int tip;
    int poz;
};
segm v[400001];
int f[200001];
int cadran (segm x){
    if (x.a<0)
        return 2;
    return 1;
}
int cmp (segm x,segm y){
    if (cadran(x)!=cadran(y))
        return cadran(x)<cadran(y);
    if ((x.o*y.a) != (x.a * y.o) && cadran(x)==1)
        return (x.o*y.a) < (x.a * y.o);
    else if ((x.o*y.a) != (x.a * y.o) && cadran(x)==2)
        return (x.o*y.a) > (x.a * y.o);
    return x.tip>y.tip;
}
int main()
{
    FILE *fin=fopen ("rays.in","r");
    FILE *fout=fopen ("rays.out","w");
    int n,s,elim,sol,i;
    long long x,y1,y2;
    fscanf (fin,"%d",&n);
    s=0;
    for (i=1;i<=n;i++){
        fscanf (fin,"%lld%lld%lld",&x,&y1,&y2);
        v[++s].a=x;
        v[s].o=min(y1,y2);
        v[s].tip=1; // incepe un segment
        v[s].poz=i;
        v[++s].a=x;
        v[s].o=max(y1,y2);
        v[s].tip=0; // se termina un segment
        v[s].poz=i;
    }
    // este gresit sa incerc sa normalizez
    sort (v+1,v+s+1,cmp); // am sortat dupa unghiul cu ox
    sol=0;
    elim=0;
    for (i=1;i<=s;i++){
        if (v[i].tip==1) // eveniment 1 : incepe un segment
            f[v[i].poz]=i;
        else {// eveniment 2 : se termina un segment
            if (f[v[i].poz]>elim){ // daca nu l am anulat cu alta ocazie
                sol++;
                elim=i;
            }
        }
    }
    fprintf (fout,"%d",sol);
    return 0;
}