Submission #799784

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
799784	2023-08-01T02:29:03 Z	junk727	Lonely mdic (kriii1_L)	C++17	1 / 1	1830 ms	320 KB

L

#include <bits/stdc++.h>
#define fastio cin.tie(0),cout.tie(0),ios::sync_with_stdio(0)
using namespace std;

typedef double ld;
typedef pair<ld,ld> pd;
#define all(x) (x).begin(),(x).end()

const ld PI = acos(-1);
const ld EPS = 1e-10;
inline bool is_zero(ld x){return -EPS<=x && x<=EPS;} 

struct circle
{
    circle() {}
    circle(int x, int y, int r) : x(x), y(y), r(r) {}

    int x,y,r;

    ld green(ld s, ld e)
    {
        ld a = r*r*(e-s);
        ld b = x * r * (sin(e)-sin(s));
        ld d = y * r * (cos(s)-cos(e));
        return (a+b+d)/2;
    }

    ld dist(const circle &m)
    {
        return (m.x-x)*(m.x-x) + (m.y-y)*(m.y-y);
    }

    ld angle(const circle &m)
    {
        return atan2((m.y-y),(m.x-x));
    }

    bool operator == (const circle &m) const {return x==m.x && y==m.y && r==m.r;}
};

int meetcc(circle c1, circle c2, ld mp[])
{
    ld d = c1.dist(c2);
    if(d > (c1.r+c2.r)*(c1.r+c2.r) + EPS) return 0; 
    if(d < (c1.r-c2.r)*(c1.r-c2.r) - EPS) return 0;

    ld ct = c1.angle(c2);

    ld temp = (c1.r*c1.r + d - c2.r*c2.r) / (2*c1.r*sqrt(d));
    if(temp<-1) temp=-1;
    if(temp>1) temp=1;
    
    auto mod = [&](ld x)
    {
        while(x<0) x+=2*PI;
        while(x>=2*PI) x-=2*PI;
        return x;
    };

    ld dt = acos(temp);
     
    int tp=0;
    if(is_zero(dt)) return tp;
    ld v1 = mod(ct-dt);
    mp[tp++] = v1;
    v1 = mod(ct+dt);
    mp[tp++] = v1;
    return tp;
}


int main()
{
    int n,ans=0; cin >> n;

    vector<circle> vc(n);

    for(int i=0;i<n;i++)
    {
        int x,y,r; cin >> x >> y >> r;
        vc[i] = {x,y,r};
    }

    vector<ld> area(n+1,0);

    sort(vc.begin(),vc.begin()+n,[](circle &p, circle &q){return p.r>q.r;});

    for(int x=0;x<=n;x++)
    {
        vector<bool> in(n,0); ld temp=0;
        for(int i=0;i<n;i++)
        {
            if(in[i] || i==x) continue;

            vector<pd> vx = {};

            for(int j=0;j<n;j++)
            {
                ld d = vc[i].dist(vc[j]);
                if(j==x || i==j || in[j] || d>=(vc[i].r+vc[j].r)*(vc[i].r+vc[j].r)) continue;
                if(d <= (vc[i].r-vc[j].r)*(vc[i].r-vc[j].r)) {in[j]=1; continue;}

                ld mp[2]; int tp = meetcc(vc[i],vc[j],mp);
                if(!tp) continue;

                if(mp[0]>mp[1]) vx.push_back({mp[0],2*PI}), vx.push_back({0,mp[1]});
                else vx.push_back({mp[0],mp[1]});
            }

            if(vx.empty()) {temp+=vc[i].r*vc[i].r*PI; continue;}
            sort(all(vx));

            vx.push_back({2*PI,2*PI});

            ld r=0;
            for(pd j : vx)
            {
                if(r<j.first) temp += vc[i].green(r,j.first), r=j.second; 
                else r=max(r,j.second);
            }
        }
        area[x]=temp;
    }

    for(int i=0;i<n;i++) if(is_zero(area[n]-area[i])) ans++;
    cout << ans;
}

Subtask #1

1.0 / 1.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	8 ms	212 KB	Output is correct
2	Correct	6 ms	212 KB	Output is correct
3	Correct	62 ms	300 KB	Output is correct
4	Correct	53 ms	212 KB	Output is correct
5	Correct	72 ms	212 KB	Output is correct
6	Correct	77 ms	212 KB	Output is correct
7	Correct	1830 ms	304 KB	Output is correct
8	Correct	140 ms	300 KB	Output is correct
9	Correct	54 ms	212 KB	Output is correct
10	Correct	461 ms	304 KB	Output is correct
11	Correct	796 ms	300 KB	Output is correct
12	Correct	107 ms	296 KB	Output is correct
13	Correct	169 ms	212 KB	Output is correct
14	Correct	67 ms	292 KB	Output is correct
15	Correct	132 ms	288 KB	Output is correct
16	Correct	13 ms	320 KB	Output is correct