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#include <cmath>
#include <algorithm>
const int MAXN = 1005;
const double PI = acos(-1);
struct {
double x, y;
Point(double x = 0, double y = 0) : x(x), y(y) {}
double angle() const {
return atan2(y, x);
}
friend double dist(const Point &a, const Point &b) {
return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
}
friend Point operator-(const Point &a, const Point &b) {
return Point(a.x - b.x, a.y - b.y);
}
};
struct Arc {
double l, r;
Arc(double l = 0, double r = 0) : l(l), r(r) {}
bool operator<(const Arc &another) const {
return l < another.l;
}
};
struct Circle {
double r;
Point o;
Circle() {}
Circle(const Point &o, double r) : o(o), r(r) {}
friend bool contain(const Circle &a, const Circle &b) {
return a.r - b.r >= dist(a.o, b.o);
}
friend Arc getCircleIntersection(const Circle &a, const Circle &b) {
double dis = dist(a.o, b.o);
double th = acos((a.r * a.r - b.r * b.r + dis * dis) / (2 * a.r * dis));
double ath = (b.o - a.o).angle();
return Arc(ath - th, ath + th);
}
} C[MAXN];
int n;
int main() {
scanf("%d", &n);
for (int i = 0; i < n; i++) scanf("%lf %lf %lf", &C[i].r, &C[i].o.x, &C[i].o.y);
double ans = 0;
for (int i = 0; i < n; i++) {
int cnt = 0;
static Arc a[MAXN];
bool flag = false;
for (int j = i + 1; j < n; j++) {
if (contain(C[j], C[i])) {
flag = true;
break;
}
if (!contain(C[i], C[j]) && C[i].r + C[j].r > dist(C[i].o, C[j].o))
a[cnt++] = getCircleIntersection(C[i], C[j]);
}
if (flag) continue;
for (int i = 0; i < cnt; i++) {
if (a[i].l < 0) a[i].l += 2 * PI;
if (a[i].r < 0) a[i].r += 2 * PI;
if (a[i].l > a[i].r) {
a[cnt++] = Arc(0, a[i].r);
a[i].r = 2 * PI;
}
}
std::sort(a, a + cnt);
double temp = 0, curr = 0;
for (int i = 0; i < cnt; i++) {
if (curr < a[i].l) {
temp += a[i].l - curr;
curr = a[i].r;
} else curr = std::max(curr, a[i].r);
}
ans += (temp + 2 * PI - curr) * C[i].r;
}
printf("%.3lfn", ans);
return 0;
}
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