답안 #597033

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
597033 2022-07-15T12:07:24 Z andrei_boaca The Forest of Fangorn (CEOI14_fangorn) C++14
10 / 100
60 ms 65536 KB
#include <bits/stdc++.h>

using namespace std;
typedef long double ld;
const ld EPS=1e-9;
int n,c,w,h;
struct point
{
    ld 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)
{
    ld a1=A.b.y-A.a.y;
    ld b1=A.a.x-A.b.x;
    ld c1=-a1*A.a.x-b1*A.a.y;

    ld a2=B.b.y-B.a.y;
    ld b2=B.a.x-B.b.x;
    ld 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);
    }
    ld x=(b1*c2-b2*c1)/(a1*b2-a2*b1);
    ld y=(-c2-a2*x)/b2;
    return {x,y};
}
ld dist(point a, point b)
{
    ld 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;
ld 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;
    ld d1=dist(L.a,L.b);
    ld d2=dist(L.a,a)+dist(a,L.b);
    return abs(d1-d2)<=EPS;
}
ld panta(line L)
{
    ld a1=L.b.y-L.a.y;
    ld b1=L.a.x-L.b.x;
    ld 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;
}
vector<line> plin,gol;
point start;
bool isbad(line L1,line L2)
{
    point comun={-1,-1};
    if(issame(L1.a,L2.a))
        comun=L1.a;
    if(issame(L1.a,L2.b))
        comun=L1.a;
    if(issame(L1.b,L2.a))
        comun=L1.b;
    if(issame(L1.b,L2.b))
        comun=L1.b;
    if(!inmat(comun))
        return 0;
    if(issame(L1.a,comun))
        swap(L1.a,L1.b);
    if(issame(L2.a,comun))
        swap(L2.a,L2.b);
    line u={G,L1.a};
    line t={G,L2.a};
    point Ui=intersect(L2,u);
    point Ti=intersect(L1,t);
    bool isu=online(Ui,u);
    bool ist=online(Ti,t);
    if(isu!=ist)
        return 0;
    else
        return 1;
}
bool comp(point a, point b)
{
    if(issame(a,start))
        return 1;
    if(issame(b,start))
        return 0;
    a.x-=start.x;
    a.y-=start.y;
    b.x-=start.x;
    b.y-=start.y;
    ld vala=0,valb=0;
    if(a.y==0)
        return 1;
    if(b.y==0)
        return 0;
    return a.x*b.y<a.y*b.x;
}
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++)
    {
        plin.clear();
        gol.clear();
        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=1;i<=n&&ok;i++)
        {
            vector<point> points;
            for(int j=1;j<=n;j++)
                if(j!=i)
                {
                    line l={tree[i],tree[j]};
                    line q={G,camps[z]};
                    point P=intersect(l,q);
                    if(inmat(P)&&online(P,q))
                        points.push_back(tree[j]);
                }
            start={1e9,1e9};
            for(point j:points)
            {
                if(j.x<start.x)
                    start=j;
                else if(j.x==start.x&&j.y==start.y)
                    start=j;
            }
            sort(points.begin(),points.end(),comp);
            for(int j=1;j<points.size();j++)
            {
                line L1={tree[i],points[j]};
                line L2={tree[i],points[j-1]};
                if(isbad(L1,L2))
                {
                    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 'ld panta(line)':
fangorn.cpp:71:8: warning: unused variable 'c1' [-Wunused-variable]
   71 |     ld c1=-a1*L.a.x-b1*L.a.y;
      |        ^~
fangorn.cpp: In function 'bool comp(point, point)':
fangorn.cpp:120:8: warning: unused variable 'vala' [-Wunused-variable]
  120 |     ld vala=0,valb=0;
      |        ^~~~
fangorn.cpp:120:15: warning: unused variable 'valb' [-Wunused-variable]
  120 |     ld vala=0,valb=0;
      |               ^~~~
fangorn.cpp: In function 'int main()':
fangorn.cpp:193:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<point>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  193 |             for(int j=1;j<points.size();j++)
      |                         ~^~~~~~~~~~~~~~
# 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 Incorrect 0 ms 340 KB Output isn't correct
5 Correct 1 ms 212 KB Output is correct
6 Incorrect 0 ms 212 KB Output isn't correct
7 Correct 2 ms 976 KB Output is correct
8 Incorrect 3 ms 992 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 2 ms 468 KB Output is correct
3 Correct 3 ms 848 KB Output is correct
4 Correct 2 ms 912 KB Output is correct
5 Correct 2 ms 912 KB Output is correct
6 Correct 6 ms 2120 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 2 ms 848 KB Output is correct
10 Correct 17 ms 5428 KB Output is correct
11 Correct 18 ms 4548 KB Output is correct
12 Incorrect 24 ms 4548 KB Output isn't correct
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Runtime error 60 ms 65536 KB Execution killed with signal 9
5 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Runtime error 49 ms 65536 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -