#include <bits/stdc++.h>
#define fastio cin.tie(0),cout.tie(0),ios::sync_with_stdio(0)
using namespace std;
#ifdef ONLINE_JUDGE
#define NDEBUG
#endif
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()
{
#ifndef NDEBUG
freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);
#else
fastio;
#endif
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;
}
Compilation message
L.cpp: In function 'int main()':
L.cpp:78:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
78 | freopen("input.txt","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
L.cpp:79:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
79 | freopen("output.txt","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
3 ms |
468 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |