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답안 #596275

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
596275 2022-07-14T14:32:28 Z andrei_boaca The Forest of Fangorn (CEOI14_fangorn) C++14
0 / 100
 244 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)
{
    if(!inmat(a))
        return 0;
    double d1=dist(L.a,L.b);
    double d2=dist(L.a,a)+dist(a,L.b);
    return abs(d1-d2)<=EPS;
}
double panta(line L)
{
    double a1=L.b.y-L.a.y;
    double b1=L.a.x-L.b.x;
    double c1=-a1*L.a.x-b1*L.a.y;
    if(b1==0)
        return 1e9;
    return (-a1)/b1;
}
bool issame(point a, point b)
{
    return abs(a.x-b.x)<=EPS&&abs(a.y-b.y)<=EPS;
}
int main()
{
    cin>>w>>h;
    cin>>G.x>>G.y;
    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++)
            lines.push_back({tree[i],tree[j]});
    for(int z=1;z<=c;z++)
    {
        vector<line> plin,gol;
        for(auto l:lines)
        {
            line q={G,camps[z]};
            point i=intersect(l,q);
            if(inmat(i)&&online(i,q))
                gol.push_back(l);
            else
                plin.push_back(l);
        }
        bool ok=1;
        for(auto L1:plin)
        {
            for(auto L2:gol)
            {
                line u={G,L2.a};
                line t={G,L2.b};
                point Ui=intersect(u,L1);
                point Ti=intersect(t,L1);
                if(inmat(Ui)&&inmat(Ti))
                    if(online(Ui,u)&&online(Ti,t))
                    {
                        ok=0;
                        break;
                    }
            }
            if(!ok)
                break;
        }
        for(int i=0;i<gol.size()&&ok;i++)
            for(int j=i+1;j<gol.size()&&ok;j++)
            {
                line L1=gol[i];
                line L2=gol[j];
                line u={G,L2.a};
                line t={G,L2.b};
                point Ui=intersect(u,L1);
                point Ti=intersect(t,L1);
                if((!online(Ui,u)||issame(Ui,L2.a))&&(!online(Ti,t)||issame(Ti,L2.b)))
                    {
                        ok=0;
                        break;
                    }
            }
        if(ok)
            sol.push_back(z);
    }
    cout<<sol.size()<<'\n';
    for(int i:sol)
        cout<<i<<' ';
    return 0;
}

Compilation message

fangorn.cpp: In function 'double panta(line)':
fangorn.cpp:72:12: warning: unused variable 'c1' [-Wunused-variable]
   72 |     double c1=-a1*L.a.x-b1*L.a.y;
      |            ^~
fangorn.cpp: In function 'int main()':
fangorn.cpp:125:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |         for(int i=0;i<gol.size()&&ok;i++)
      |                     ~^~~~~~~~~~~
fangorn.cpp:126:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<line>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  126 |             for(int j=i+1;j<gol.size()&&ok;j++)
      |                           ~^~~~~~~~~~~

Subtask #1
0.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 0 ms 212 KB Output isn't correct
2 Correct 0 ms 212 KB Output is correct
3 Incorrect 0 ms 212 KB Output isn't correct
4 Correct 0 ms 212 KB Output is correct
5 Incorrect 0 ms 212 KB Output isn't correct
6 Incorrect 1 ms 212 KB Output isn't correct
7 Correct 1 ms 556 KB Output is correct
8 Incorrect 5 ms 596 KB Output isn't correct

Subtask #2
0.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 340 KB Output is correct
2 Incorrect 8 ms 404 KB Output isn't correct
3 Incorrect 55 ms 616 KB Output isn't correct
4 Correct 2 ms 596 KB Output is correct
5 Correct 2 ms 596 KB Output is correct
6 Correct 9 ms 1104 KB Output is correct
7 Incorrect 1 ms 212 KB Output isn't correct
8 Incorrect 1 ms 212 KB Output isn't correct
9 Incorrect 13 ms 580 KB Output isn't correct
10 Incorrect 244 ms 2384 KB Output isn't correct
11 Incorrect 20 ms 2552 KB Output isn't correct
12 Correct 134 ms 2512 KB Output is correct

Subtask #3
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 5 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 48 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -