Cod sursa(job #597942)

Utilizator drywaterLazar Vlad drywater Data 24 iunie 2011 01:00:48
Problema Poligon Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 2.43 kb
#include <fstream>
#include <algorithm>
#define fi first
#define se second
using namespace std;
ifstream f("poligon.in");
ofstream o("poligon.out");
struct dreapta{int a; int b; int c;};
dreapta a[801];
struct banda{pair<double,int> v[801];};
banda bv[801];
int n,m,v[801][2],x,y,i,j,xu[801],nr,k,sol,sol2,s,xf[801],p,x1,y1,x2,y2,pe_lat;
inline int mini(int a,int b)
{
    if (a<b) return a;
    return b;
}
inline int maxi(int a,int b)
{
    if (a<b) return b;
    return a;
}
int main(void)
{
    f>>n>>m;
    for (i=1;i<=n;i++)
    {
        f>>v[i][0]>>v[i][1];
        if (i>1)
        {
            a[i-1].a=v[i-1][1]-v[i][1];
            a[i-1].b=v[i][0]-v[i-1][0];
            a[i-1].c=v[i-1][0]*v[i][1]-v[i-1][1]*v[i][0];
            if (a[i-1].b<0) {a[i-1].a*=(-1); a[i-1].b*=(-1); a[i-1].c*=(-1);}
        }
        xu[i]=v[i][0];
    }
    v[i][0]=v[1][0];
    v[i][1]=v[1][1];
    a[i-1].a=v[i-1][1]-v[i][1];
    a[i-1].b=v[i][0]-v[i-1][0];
    a[i-1].c=v[i-1][0]*v[i][1]-v[i-1][1]*v[i][0];
    if (a[i-1].b<0)
    {a[i-1].a*=(-1); a[i-1].b*=(-1); a[i-1].c*=(-1);}
    sort(xu+1,xu+n+1);
    p=0;
    for (i=1;i<=n;i++)
    {
        if (i==1 || xu[i]!=xu[i-1])
            xf[++p]=xu[i];
    }
    for (i=1;i<p;i++)
    {
        for (j=1;j<=n;j++)
        {
            if (mini(v[j][0],v[j+1][0])<=xf[i] && maxi(v[j+1][0],v[j][0])>=xf[i+1])
            {
                double aa,b,c,x,y;
                aa=a[j].a;
                b=a[j].b;
                c=a[j].c;
                x=xf[i]+xf[i+1];
                x/=2;
                y=(-1)*(aa*x+c)/b;
                bv[i].v[++bv[i].v[0].se]=make_pair(y,j);

            }
        }
        sort(bv[i].v+1,bv[i].v+bv[i].v[0].se+1);
    }
    for (i=1;i<=m;i++)
    {
        f>>x>>y;
        if (x<xf[1] || x>xf[p]) continue;
        k=1;
        while (k<=p) k*=2;
        k/=2;
        sol=0;
        while (k>0)
        {
            if (sol+k<p && xf[sol+k]<=x) sol+=k;
            k/=2;
        }
        sol2=0;
        k=1;
        while (k<=bv[sol].v[0].se) k*=2;
        k/=2;
        while (k>0)
        {
            s=bv[sol].v[sol2+k].se;
            if (a[s].a*x+a[s].b*y+a[s].c==0) pe_lat=1;
            if (sol2+k<=bv[sol].v[0].se && a[s].a*x+a[s].b*y+a[s].c<0) sol2+=k;
            k/=2;
        }
        if (sol2%2!=0 || pe_lat) nr++;
        pe_lat=0;
    }
    o<<nr<<"\n";
    return 0;
}