#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 long double ld;
typedef pair<ld,ld> pd;
#define all(x) (x).begin(),(x).end()
const ld PI = acos(-1);
const ld EPS = 1e-27;
inline bool is_zero(ld x){return -EPS<=x && x<=EPS;}
struct point
{
point() {}
point(ld x, ld y) : x(x),y(y) {}
ld x,y;
point operator + (const point &p) const {return{x+p.x,y+p.y};}
point operator - (const point &p) const {return{x-p.x,y-p.y};}
ld len() {return x*x+y*y;}
ld angle() {return atan2(y,x);}
};
struct circle
{
circle() {}
circle(point c, int r, int id) : c(c), r(r), id(id) {}
point c;
int r,id;
ld green(ld s, ld e)
{
ld a = r*r*(e-s);
ld b = c.x * r * (sin(e)-sin(s));
ld d = c.y * r * (cos(s)-cos(e));
return (a+b+d)/2;
}
};
ld mod(ld x)
{
while(x<0) x+=2*PI;
while(x>=2*PI) x-=2*PI;
return x;
}
int main()
{
#ifndef NDEBUG
freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);
#else
fastio;
#endif
int n; cin >> n;
vector<circle> vc;
vector<bool> in(n,0);
vector<ld> area(n,0);
for(int i=0;i<n;++i)
{
int x,y,r; cin >> x >> y >> r;
vc.push_back({{(ld)x,(ld)y},r,i});
}
sort(all(vc),[](circle &p, circle &q){return p.r>q.r;});
for(int x=0;x<n;++x)
{
in.clear(); 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++)
{
point pt = vc[j].c-vc[i].c; ld d = pt.len();
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 z = pt.angle(), dt = acos((vc[i].r*vc[i].r+d-vc[j].r*vc[j].r)/(2*vc[i].r*sqrt(d)));
ld l = mod(z-dt), r = mod(z+dt);
if(l>r) vx.push_back({0,r}), vx.push_back({l,2*PI});
else vx.push_back({l,r});
}
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;
}
in.clear(); ld comp=0;
for(int i=0;i<n;i++)
{
if(in[i]) continue;
vector<pd> vx = {};
for(int j=0;j<n;j++)
{
point pt = vc[j].c-vc[i].c; ld d = pt.len();
if(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 z = pt.angle(), dt = acos((vc[i].r*vc[i].r+d-vc[j].r*vc[j].r)/(2*vc[i].r*sqrt(d)));
ld l = mod(z-dt), r = mod(z+dt);
if(l>r) vx.push_back({0,r}), vx.push_back({l,2*PI});
else vx.push_back({l,r});
}
if(vx.empty()) {comp+=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) comp += vc[i].green(r,j.first), r=j.second;
else r=max(r,j.second);
}
}
int ans=0;
for(int i=0;i<n;i++) if(is_zero(comp-area[i])) ans++;
cout << ans;
}
Compilation message
L.cpp: In function 'int main()':
L.cpp:57:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
57 | freopen("input.txt","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
L.cpp:58:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
58 | freopen("output.txt","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
2 ms |
468 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |