답안 #596053

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
596053 2022-07-14T09:45:31 Z andrei_boaca The Forest of Fangorn (CEOI14_fangorn) C++14
0 / 100
893 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=360;
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<bool> f;
    f.resize((int)lines.size());
    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&&EPS<up.y-a.y)
                {
                    up=a;
                    lup=i;
                }
                if(a.y<=p.y-EPS&&a.y-down.y>EPS)
                {
                    down=a;
                    ldown=i;
                }
            }
        }
        if(lup>=0&&f[lup]==0)
        {
            f[lup]=1;
            mylines.push_back(lup);
            ups.push_back(up);
        }
        if(ldown>=0&&f[ldown]==0)
        {
            f[ldown]=1;
            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:84:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |         for(int i=0;i<lines.size();i++)
      |                     ~^~~~~~~~~~~~~
fangorn.cpp:135:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<point>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  135 |     for(int i=2;i<poli.size();i++)
      |                 ~^~~~~~~~~~~~
fangorn.cpp: In function 'int main()':
fangorn.cpp:153:31: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  153 |     lines.push_back({{0,0},{0,h}});
      |                               ^
fangorn.cpp:154:29: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  154 |     lines.push_back({{0,0},{w,0}});
      |                             ^
fangorn.cpp:155:23: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  155 |     lines.push_back({{w,h},{0,h}});
      |                       ^
fangorn.cpp:155:25: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  155 |     lines.push_back({{w,h},{0,h}});
      |                         ^
fangorn.cpp:155:31: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  155 |     lines.push_back({{w,h},{0,h}});
      |                               ^
fangorn.cpp:156:23: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  156 |     lines.push_back({{w,h},{w,0}});
      |                       ^
fangorn.cpp:156:25: warning: narrowing conversion of 'h' from 'int' to 'double' [-Wnarrowing]
  156 |     lines.push_back({{w,h},{w,0}});
      |                         ^
fangorn.cpp:156:29: warning: narrowing conversion of 'w' from 'int' to 'double' [-Wnarrowing]
  156 |     lines.push_back({{w,h},{w,0}});
      |                             ^
fangorn.cpp:206:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  206 |                 for(int j=0;j<mylines.size();j++)
      |                             ~^~~~~~~~~~~~~~~
# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 212 KB Output is correct
2 Incorrect 1 ms 212 KB Output isn't correct
3 Incorrect 1 ms 212 KB Output isn't correct
4 Correct 7 ms 212 KB Output is correct
5 Incorrect 1 ms 212 KB Output isn't correct
6 Incorrect 3 ms 212 KB Output isn't correct
7 Incorrect 175 ms 596 KB Output isn't correct
8 Incorrect 136 ms 596 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Incorrect 53 ms 396 KB Output isn't correct
2 Incorrect 94 ms 468 KB Output isn't correct
3 Correct 214 ms 596 KB Output is correct
4 Incorrect 259 ms 596 KB Output isn't correct
5 Incorrect 272 ms 596 KB Output isn't correct
6 Incorrect 741 ms 1356 KB Output isn't correct
7 Incorrect 1 ms 212 KB Output isn't correct
8 Correct 7 ms 340 KB Output is correct
9 Incorrect 171 ms 596 KB Output isn't correct
10 Incorrect 893 ms 1484 KB Output isn't correct
11 Correct 848 ms 2504 KB Output is correct
12 Incorrect 649 ms 1356 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Incorrect 9 ms 212 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Runtime error 90 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -