Submission #596045

# Submission time Handle Problem Language Result Execution time Memory
596045 2022-07-14T09:34:11 Z andrei_boaca The Forest of Fangorn (CEOI14_fangorn) C++14
0 / 100
90 ms 65536 KB
#include <bits/stdc++.h>

using namespace std;
const double EPS=1e-9;
int n,c,w,h;
struct point
{
    double x,y;
} G,camps[10005],tree[10005];
struct line
{
    point a,b;
};
vector<line> lines;
bool inmat(point p)
{
    return p.x>=0&&p.x<=w&&p.y>=0&&p.y<=h;
}
point intersect(line A, line B)
{
    double a1=A.b.y-A.a.y;
    double b1=A.a.x-A.b.x;
    double c1=-a1*A.a.x-b1*A.a.y;

    double a2=B.b.y-B.a.y;
    double b2=B.a.x-B.b.x;
    double c2=-a2*B.a.x-b2*B.a.y;

    if(a1==0&&a2==0)
        return {-1,-1};
    if(b1==0&&b2==0)
        return {-1,-1};
    if(b2==0)
    {
        swap(a1,a2);
        swap(b1,b2);
        swap(c1,c2);
    }
    double x=(b1*c2-b2*c1)/(a1*b2-a2*b1);
    double y=(-c2-a2*x)/b2;
    return {x,y};
}
double dist(point a, point b)
{
    double val=(a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);
    return sqrt(val);
}
vector<int> mylines,sol,Glines;
bool conv=0;
const double beams=15;
const double PI=3.14159265359;
double aria(point a, point b, point c)
{
    a.x-=c.x;
    a.y-=c.y;
    b.x-=c.x;
    b.y-=c.y;
    return a.x*b.y-a.y*b.x;
}
bool online(point a, line L)
{
    double d1=dist(L.a,L.b);
    double d2=dist(L.a,a)+dist(a,L.b);
    return abs(d1-d2)<=EPS;
}
bool prt=0;
void laser(point p)
{
    mylines.clear();
    conv=1;
    double grade=0,rad=0;
    double ip=10.0;
    vector<point> ups,downs,poli;
    while(grade<=beams)
    {
        double x=ip*cos(rad)+p.x;
        double y=ip*sin(rad)+p.y;
        point q={x,y};
        point up={1e9,1e9},down={-1e9,-1e9};
        int lup=-1,ldown=-1;
        line l={p,q};
        for(int i=0;i<lines.size();i++)
        {
            point a=intersect(l,lines[i]);
            if(inmat(a)&&online(a,lines[i]))
            {
                if(a.y>=p.y+EPS&&a.y<up.y)
                {
                    up=a;
                    lup=i;
                }
                if(a.y<=p.y-EPS&&a.y>down.y)
                {
                    down=a;
                    ldown=i;
                }
            }
        }
        if(lup>=0)
        {
            mylines.push_back(lup);
            ups.push_back(up);
        }
        if(ldown>=0)
        {
            mylines.push_back(ldown);
            downs.push_back(down);
        }
        grade++;
        rad+=PI/beams;
    }
    reverse(downs.begin(),downs.end());
    for(auto i:ups)
        poli.push_back(i);
    for(auto i:downs)
        poli.push_back(i);
    sort(mylines.begin(),mylines.end());
    mylines.erase(unique(mylines.begin(),mylines.end()),mylines.end());
    if(prt)
    {
        /*for(auto i:poli)
            cout<<i.x<<' '<<i.y<<'\n';*/
        /*for(auto i:mylines)
        {
            line l=lines[i];
            cout<<l.a.x<<' '<<l.a.y<<' '<<l.b.x<<' '<<l.b.y<<'\n';
        }
        cout<<'\n';*/
    }
    conv=1;
    for(int i=2;i<poli.size();i++)
    {
        point a=poli[i-2];
        point b=poli[i-1];
        point c=poli[i];
        /*if(prt)
            cout<<aria(a,b,c)<<'\n';*/
        if(aria(a,b,c)>0)
        {
            conv=0;
            break;
        }
    }
}
int main()
{
    cin>>w>>h;
    cin>>G.x>>G.y;
    lines.push_back({{0,0},{0,h}});
    lines.push_back({{0,0},{w,0}});
    lines.push_back({{w,h},{0,h}});
    lines.push_back({{w,h},{w,0}});
    cin>>c;
    for(int i=1;i<=c;i++)
        cin>>camps[i].x>>camps[i].y;
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>tree[i].x>>tree[i].y;
    for(int i=1;i<=n;i++)
        for(int j=i+1;j<=n;j++)
        {
            line l={tree[i],tree[j]};
            for(int p=0;p<4;p++)
            {
                point a=intersect(lines[p],l);
                if(inmat(a))
                {
                    double d=dist(tree[i],a)+dist(tree[i],tree[j]);
                    double d2=dist(tree[j],a);
                    if(abs(d-d2)<=EPS)
                        lines.push_back({tree[i],a});
                    else
                        lines.push_back({tree[j],a});
                }
            }
        }
    laser(G);
    if(conv==0)
        mylines.clear();
    else
    {
        Glines=mylines;
        sort(Glines.begin(),Glines.end());
        Glines.erase(unique(Glines.begin(),Glines.end()),Glines.end());
    }
    for(int i=1;i<=c;i++)
    {
        if(i==2)
            prt=1;
        else
            prt=0;
        laser(camps[i]);
        if(conv)
        {
            if(Glines.empty())
                continue;
            sort(mylines.begin(),mylines.end());
            mylines.erase(unique(mylines.begin(),mylines.end()),mylines.end());
            if(mylines.size()==Glines.size())
            {
                bool ok=1;
                for(int j=0;j<mylines.size();j++)
                    if(mylines[j]!=Glines[j])
                        ok=0;
                if(ok)
                    sol.push_back(i);
            }
        }
        else
        {
            if(Glines.empty())
                sol.push_back(i);
        }
    }
    cout<<sol.size()<<'\n';
    for(int i:sol)
        cout<<i<<' ';
    return 0;
}

Compilation message

fangorn.cpp: In function 'void laser(point)':
fangorn.cpp:82:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |         for(int i=0;i<lines.size();i++)
      |                     ~^~~~~~~~~~~~~
fangorn.cpp:131:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<point>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  131 |     for(int i=2;i<poli.size();i++)
      |                 ~^~~~~~~~~~~~
fangorn.cpp: In function 'int main()':
fangorn.cpp:149:31: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  149 |     lines.push_back({{0,0},{0,h}});
      |                               ^
fangorn.cpp:150:29: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  150 |     lines.push_back({{0,0},{w,0}});
      |                             ^
fangorn.cpp:151:23: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  151 |     lines.push_back({{w,h},{0,h}});
      |                       ^
fangorn.cpp:151:25: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  151 |     lines.push_back({{w,h},{0,h}});
      |                         ^
fangorn.cpp:151:31: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  151 |     lines.push_back({{w,h},{0,h}});
      |                               ^
fangorn.cpp:152:23: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  152 |     lines.push_back({{w,h},{w,0}});
      |                       ^
fangorn.cpp:152:25: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  152 |     lines.push_back({{w,h},{w,0}});
      |                         ^
fangorn.cpp:152:29: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  152 |     lines.push_back({{w,h},{w,0}});
      |                             ^
fangorn.cpp:202:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  202 |                 for(int j=0;j<mylines.size();j++)
      |                             ~^~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Output isn't correct
2 Correct 1 ms 308 KB Output is correct
3 Incorrect 1 ms 212 KB Output isn't correct
4 Incorrect 1 ms 312 KB Output isn't correct
5 Incorrect 1 ms 212 KB Output isn't correct
6 Incorrect 1 ms 312 KB Output isn't correct
7 Incorrect 9 ms 596 KB Output isn't correct
8 Incorrect 7 ms 596 KB Output isn't correct
# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 340 KB Output isn't correct
2 Incorrect 5 ms 468 KB Output isn't correct
3 Incorrect 10 ms 596 KB Output isn't correct
4 Incorrect 16 ms 596 KB Output isn't correct
5 Incorrect 13 ms 696 KB Output isn't correct
6 Incorrect 38 ms 1484 KB Output isn't correct
7 Incorrect 1 ms 212 KB Output isn't correct
8 Correct 1 ms 340 KB Output is correct
9 Incorrect 8 ms 596 KB Output isn't correct
10 Incorrect 55 ms 1484 KB Output isn't correct
11 Correct 53 ms 2504 KB Output is correct
12 Incorrect 31 ms 1484 KB Output isn't correct
# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 212 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 90 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -