QOJ.ac
QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#35597 | #972. Circle | AutumnKite | WA | 651ms | 4324kb | C++17 | 17.3kb | 2022-06-17 10:40:53 | 2022-06-17 10:40:53 |
Judging History
answer
#include <bits/stdc++.h>
template<typename Tp, typename Comp>
class geometry {
public:
static constexpr Tp pi = 3.14159265358979324L;
static int sgn(const Tp &a, const Tp &b = Tp()) {
static Comp cmp;
return cmp(a, b) ? -1 : (cmp(b, a) ? 1 : 0);
}
static Tp safe_sqrt(const Tp &a) {
if (!sgn(a)) {
return Tp();
} else {
return std::sqrt(a);
}
}
struct point {
Tp x, y;
point() : x(), y() {}
point(const Tp &t_x, const Tp &t_y) : x(t_x), y(t_y) {}
Tp len2() const {
return x * x + y * y;
}
Tp len() const {
return safe_sqrt(len2());
}
point unit2() const {
Tp l = len2();
if (!sgn(l)) {
return point();
}
return point(x / l, y / l);
}
point unit() const {
Tp l = len();
if (!sgn(l)) {
return point();
}
return point(x / l, y / l);
}
Tp angle() const {
Tp t = std::atan2(y, x);
if (sgn(t) < 0) {
t += 2 * pi;
}
return t;
}
point rotate(Tp th) const {
return point(x * std::cos(th) - y * std::sin(th),
y * std::cos(th) + x * std::sin(th));
}
point rotate90() const {
return point(-y, x);
}
point &operator+=(const point &rhs) {
x += rhs.x, y += rhs.y;
return *this;
}
point &operator-=(const point &rhs) {
x -= rhs.x, y -= rhs.y;
return *this;
}
point &operator*=(const Tp &rhs) {
x *= rhs, y *= rhs;
return *this;
}
point &operator/=(const Tp &rhs) {
x /= rhs, y /= rhs;
return *this;
}
bool sgn_equal(const point &rhs) const {
return !sgn(x, rhs.x) && !sgn(y, rhs.y);
}
friend point operator+(const point &lhs, const point &rhs) {
return point(lhs.x + rhs.x, lhs.y + rhs.y);
}
friend point operator-(const point &lhs, const point &rhs) {
return point(lhs.x - rhs.x, lhs.y - rhs.y);
}
friend point operator*(const point &lhs, const Tp &rhs) {
return point(lhs.x * rhs, lhs.y * rhs);
}
friend point operator*(const Tp &lhs, const point &rhs) {
return point(lhs * rhs.x, lhs * rhs.y);
}
friend point operator/(const point &lhs, const Tp &rhs) {
return point(lhs.x / rhs, lhs.y / rhs);
}
friend bool operator==(const point &lhs, const point &rhs) {
return lhs.x == rhs.x && lhs.y == rhs.y;
}
friend bool operator<(const point &lhs, const point &rhs) {
return lhs.x < rhs.x || (lhs.x == rhs.x && lhs.y < rhs.y);
}
friend std::istream &operator>>(std::istream &in, point &p) {
return in >> p.x >> p.y;
}
friend std::ostream &operator<<(std::ostream &out, const point &p) {
return out << p.x << " " << p.y;
}
};
static Tp dot(const point &a, const point &b) {
return a.x * b.x + a.y * b.y;
}
static Tp cross(const point &a, const point &b) {
return a.x * b.y - a.y * b.x;
}
static Tp angle(const point &a, const point &b) {
Tp t = std::atan2(cross(a, b), dot(a, b));
if (sgn(t) < 0) {
t += 2 * pi;
}
return t;
}
static Tp distance2(const point &a, const point &b) {
return (a - b).len2();
}
static Tp distance(const point &a, const point &b) {
return (a - b).len();
}
enum direction_t {
COUNTER_CLOCKWISE,
CLOCKWISE,
ONLINE_BACK,
ONLINE_FRONT,
ON_SEGMENT
};
struct line {
point a, b;
line() : a(), b() {}
line(const point &t_a, const point &t_b) : a(t_a), b(t_b) {}
Tp get_Y(const Tp &X) const {
if (sgn(a.x, b.x) == 0) {
return a.y;
}
return (a + (X - a.x) / (b.x - a.x) * (b - a)).y;
}
line rev() const {
return line(b, a);
}
direction_t direction(const point &p) const {
int t = sgn(cross(b - a, p - a));
if (t > 0) {
return COUNTER_CLOCKWISE;
}
if (t < 0) {
return CLOCKWISE;
}
Tp l1 = dot(p - a, b - a);
if (sgn(l1) < 0) {
return ONLINE_BACK;
}
Tp l2 = dot(b - a, b - a);
if (sgn(l1, l2) > 0) {
return ONLINE_FRONT;
}
return ON_SEGMENT;
}
point midpoint() const {
return (a + b) / 2;
}
line vertical_bisector() const {
point p = midpoint();
return line(p, p + (b - p).rotate90());
}
};
static bool parallel(const line &a, const line &b) {
return !sgn(cross(a.b - a.a, b.b - b.a));
}
static point projection(const line &l, const point &p) {
return l.a + (l.b - l.a).unit2() * dot(p - l.a, l.b - l.a);
}
static std::vector<point> line_cross(const line &a, const line &b) {
if (parallel(a, b)) {
return {};
}
point u = a.a - b.a, v = a.b - a.a, w = b.b - b.a;
return {a.a + cross(w, u) / cross(v, w) * v};
}
static std::vector<point> segment_cross(const line &a, const line &b) {
Tp t1 = cross(b.a - a.a, a.b - a.a), t2 = cross(b.b - a.a, a.b - a.a);
Tp t3 = cross(a.a - b.a, b.b - b.a), t4 = cross(a.b - b.a, b.b - b.a);
if (!sgn(t1) && !sgn(t2) && !sgn(t3) && !sgn(t4)) {
if (sgn(std::min(a.a.x, a.b.x), std::max(b.a.x, b.b.x)) > 0) {
return {};
}
if (sgn(std::min(b.a.x, b.b.x), std::max(a.a.x, a.b.x)) > 0) {
return {};
}
if (sgn(std::min(a.a.y, a.b.y), std::max(b.a.y, b.b.y)) > 0) {
return {};
}
if (sgn(std::min(b.a.y, b.b.y), std::max(a.a.y, a.b.y)) > 0) {
return {};
}
return {std::max(std::min(a.a, a.b), std::min(b.a, b.b)),
std::min(std::max(a.a, a.b), std::max(b.a, b.b))};
}
if (sgn(t1) * sgn(t2) > 0) {
return {};
}
if (sgn(t3) * sgn(t4) > 0) {
return {};
}
return line_cross(a, b);
}
static std::vector<point> segment_set_cross(const std::vector<line> &s) {
using pointer = typename std::vector<line>::const_iterator;
std::vector<std::tuple<Tp, bool, pointer>> op;
for (pointer it = s.begin(); it != s.end(); ++it) {
if (sgn(it->a.x, it->b.x) > 0) {
op.emplace_back(it->a.x, true, it);
op.emplace_back(it->b.x, false, it);
} else {
op.emplace_back(it->a.x, false, it);
op.emplace_back(it->b.x, true, it);
}
}
std::sort(op.begin(), op.end(), [&](const auto &a, const auto &b) {
int t = sgn(std::get<0>(a), std::get<0>(b));
if (t) {
return t < 0;
}
return std::make_pair(std::get<1>(a), std::get<2>(a)) <
std::make_pair(std::get<1>(b), std::get<2>(b));
});
Tp now = 0;
std::function<bool(pointer, pointer)> cmp = [&](pointer i, pointer j) {
int t = sgn(i->get_Y(now), j->get_Y(now));
if (t) {
return t < 0;
}
return i < j;
};
std::set<pointer, decltype(cmp)> S(cmp);
bool ok = false;
point ans;
auto upd = [&](pointer i, pointer j) {
auto tmp = segment_cross(*i, *j);
if (!tmp.empty()) {
if (!ok) {
ok = true;
ans = *tmp.begin();
} else {
ans = std::min(ans, *tmp.begin());
}
}
return tmp;
};
for (auto p : op) {
now = std::get<0>(p);
if (ok && sgn(ans.x, now) < 0) {
break;
}
pointer it = std::get<2>(p);
if (std::get<1>(p)) {
S.erase(it);
auto nx = S.upper_bound(it);
if (nx != S.begin() && nx != S.end()) {
upd(*std::prev(nx), *nx);
}
} else {
auto nx = S.upper_bound(it);
if (nx != S.end()) {
upd(it, *nx);
}
if (nx != S.begin()) {
upd(*std::prev(nx), it);
}
S.insert(it);
}
}
if (ok) {
return {ans};
} else {
return {};
}
}
using polygon = std::vector<point>;
static polygon convex_hull(std::vector<point> f) {
if (f.empty()) {
return polygon();
}
std::size_t t = 0;
for (std::size_t i = 1; i < f.size(); ++i) {
if (f[i].y < f[t].y || (f[i].y == f[t].y && f[i].x < f[t].x)) {
t = i;
}
}
std::rotate(f.begin(), f.begin() + t, f.end());
std::sort(f.begin() + 1, f.end(), [&](const point &p, const point &q) {
int tmp = sgn(cross(p - f[0], q - f[0]));
if (tmp) {
return tmp > 0;
}
return distance(p, f[0]) < distance(q, f[0]);
});
polygon p;
for (std::size_t i = 0; i < f.size(); ++i) {
while (p.size() > 1 &&
cross(f[i] - p.back(), p[p.size() - 2] - p.back()) <= 0) {
p.pop_back();
}
p.push_back(f[i]);
}
return p;
}
static polygon convex_cut(const polygon &g, const line &l) {
polygon res;
for (std::size_t i = 0; i < g.size(); ++i){
point u = g[i], v = g[(i + 1) % g.size()];
if (sgn(cross(l.b - l.a, u - l.a)) >= 0) {
res.push_back(u);
if (sgn(cross(l.b - l.a, v - l.a)) < 0) {
res.push_back(line_cross(line(u, v), l)[0]);
}
} else if (sgn(cross(l.b - l.a, v - l.a)) > 0) {
res.push_back(line_cross(line(u, v), l)[0]);
}
}
return res;
}
static Tp polygon_directed_area(const polygon &g) {
Tp s = 0;
for (std::size_t i = 0; i < g.size(); ++i) {
s += cross(g[i], g[(i + 1) % g.size()]);
}
return s / 2;
}
static polygon half_plane_intersection(const std::vector<line> &ls,
const point &min, const point &max) {
std::vector<std::pair<Tp, line>> f;
for (const auto &l : ls) {
f.emplace_back(0, l);
}
f.emplace_back(0, line(point(min.x, min.y), point(max.x, min.y)));
f.emplace_back(0, line(point(max.x, min.y), point(max.x, max.y)));
f.emplace_back(0, line(point(max.x, max.y), point(min.x, max.y)));
f.emplace_back(0, line(point(min.x, max.y), point(min.x, min.y)));
for (auto &p : f) {
p.first = (p.second.b - p.second.a).angle();
}
std::sort(f.begin(), f.end(), [&](const auto &a, const auto &b) {
int t = sgn(a.first, b.first);
if (t) {
return t < 0;
}
return a.second.direction(b.second.a) == CLOCKWISE;
});
std::deque<line> Ql;
std::deque<point> Qp;
Ql.push_back(f[0].second);
for (std::size_t i = 1; i < f.size(); ++i) {
if (sgn(f[i - 1].first, f[i].first)) {
while (!Qp.empty() && f[i].second.direction(Qp.back()) == CLOCKWISE) {
Qp.pop_back();
Ql.pop_back();
}
while (!Qp.empty() && f[i].second.direction(Qp.front()) == CLOCKWISE) {
Qp.pop_front();
Ql.pop_front();
}
auto tmp = line_cross(Ql.back(), f[i].second);
if (tmp.empty()) {
return polygon();
}
Qp.push_back(tmp[0]);
Ql.push_back(f[i].second);
}
}
while (!Qp.empty() && Ql.front().direction(Qp.back())) {
Qp.pop_back();
Ql.pop_back();
}
if (Ql.size() < 3) {
return polygon();
}
auto tmp = line_cross(Ql.back(), Ql.front());
if (tmp.empty()) {
return polygon();
}
Qp.push_back(tmp[0]);
return polygon(Qp.begin(), Qp.end());
}
static std::vector<std::size_t> half_plane_intersection_id(
const std::vector<line> &ls, const point &min, const point &max) {
std::vector<std::pair<std::pair<Tp, std::size_t>, line>> f;
for (std::size_t i = 0; i < ls.size(); ++i) {
f.emplace_back(std::pair<Tp, std::size_t>(0, i), ls[i]);
}
std::pair<Tp, std::size_t> add(0, -1);
f.emplace_back(add, line(point(min.x, min.y), point(max.x, min.y)));
f.emplace_back(add, line(point(max.x, min.y), point(max.x, max.y)));
f.emplace_back(add, line(point(max.x, max.y), point(min.x, max.y)));
f.emplace_back(add, line(point(min.x, max.y), point(min.x, min.y)));
for (auto &p : f) {
p.first.first = (p.second.b - p.second.a).angle();
}
std::sort(f.begin(), f.end(), [&](const auto &a, const auto &b) {
int t = sgn(a.first.first, b.first.first);
if (t) {
return t < 0;
}
return a.second.direction(b.second.a) == CLOCKWISE;
});
std::deque<std::pair<std::size_t, line>> Ql;
std::deque<point> Qp;
Ql.emplace_back(f[0].first.second, f[0].second);
for (std::size_t i = 1; i < f.size(); ++i) {
if (sgn(f[i - 1].first.first, f[i].first.first)) {
while (!Qp.empty() && f[i].second.direction(Qp.back()) == CLOCKWISE) {
Qp.pop_back();
Ql.pop_back();
}
while (!Qp.empty() && f[i].second.direction(Qp.front()) == CLOCKWISE) {
Qp.pop_front();
Ql.pop_front();
}
auto tmp = line_cross(Ql.back().second, f[i].second);
if (tmp.empty()) {
return std::vector<std::size_t>();
}
Qp.push_back(tmp[0]);
Ql.emplace_back(f[i].first.second, f[i].second);
}
}
while (!Qp.empty() && Ql.front().second.direction(Qp.back())) {
Qp.pop_back();
Ql.pop_back();
}
if (Ql.size() < 3) {
return std::vector<std::size_t>();
}
auto tmp = line_cross(Ql.back().second, Ql.front().second);
if (tmp.empty()) {
return std::vector<std::size_t>();
}
Qp.push_back(tmp[0]);
std::vector<std::size_t> res;
for (const auto &p : Ql) {
if (p.first != add.second) {
res.push_back(p.first);
}
}
return res;
}
struct circle {
point o;
Tp r;
circle() : o(), r() {}
circle(const point &t_o, const Tp &t_r) : o(t_o), r(t_r) {}
};
static int circle_point_relation(const circle &a, const point &p) {
return sgn(distance2(a.o, p), a.r * a.r);
}
static std::vector<point> circle_cross(const circle &a, const circle &b) {
Tp d = distance(a.o, b.o);
if (sgn(d, a.r + b.r) > 0 || sgn(d, std::abs(a.r - b.r)) < 0 || !sgn(d)) {
return {};
}
Tp x = (a.r * a.r - b.r * b.r + d * d) / (d * 2);
Tp h = safe_sqrt(a.r * a.r - x * x);
point p = a.o + x * (b.o - a.o).unit();
point v = h * (b.o - a.o).unit().rotate90();
if (!sgn(v.x) && !sgn(v.y)) {
return {p};
} else {
return {p - v, p + v};
}
}
static std::vector<point> circle_tangent(const circle &a, const point &p) {
Tp d = distance(a.o, p);
int t = sgn(d, a.r);
if (t < 0) {
return {};
} else if (t == 0) {
return {p};
} else {
return circle_cross(circle(p, safe_sqrt(d * d - a.r * a.r)), a);
}
}
static std::vector<point> circle_common_tangent_out(const circle &a,
const circle &b) {
if (!sgn(a.r, b.r)) {
point p = (a.o - b.o).unit().rotate90() * a.r;
return {a.o - p, a.o + p};
}
point p = (a.o * b.r - b.o * a.r) / (b.r - a.r);
return circle_tangent(a, p);
}
static std::vector<point> circle_line_cross(const circle &c, const line &l) {
point p = projection(line(l.a, l.b), c.o), v = (l.b - l.a).unit();
Tp d = distance(p, c.o);
if (sgn(d, c.r) > 0) {
return {};
}
Tp t = sqrt(c.r * c.r - (p - c.o).len2());
if (!sgn(t)) {
return {p};
} else {
return {p - v * t, p + v * t};
}
}
};
struct double_compare {
constexpr bool operator()(const double &a, const double &b) const {
return a + 1e-9 <= b;
}
};
using geo = geometry<double, double_compare>;
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(nullptr);
std::cout.setf(std::ios::fixed);
std::cout.precision(3);
int T;
std::cin >> T;
while (T--) {
geo::point A, B;
geo::circle C;
std::cin >> A >> B >> C.o >> C.r;
auto pA = geo::circle_tangent(C, A);
auto pB = geo::circle_tangent(C, B);
if (pA.size() == 1) {
pA.push_back(pA[0]);
}
if (pB.size() == 1) {
pB.push_back(pB[0]);
}
auto tmp = geo::circle_line_cross(C, geo::line(A, B));
if (!tmp.empty() && geo::line(A, B).direction(tmp[0]) == geo::ON_SEGMENT) {
double s0 = geo::distance(A, pA[0]) + geo::distance(B, pB[1]) +
geo::angle(pA[0] - C.o, pB[1] - C.o) * C.r;
double s1 = geo::distance(B, pB[0]) + geo::distance(A, pA[1]) +
geo::angle(pB[0] - C.o, pA[1] - C.o) * C.r;
std::cout << std::min(s0, s1) << "\n";
continue;
}
double l, r;
if (geo::sgn(geo::cross(pA[1] - C.o, pB[1] - C.o)) > 0) {
l = (pB[1] - C.o).angle();
} else {
l = (pA[1] - C.o).angle();
}
if (geo::sgn(geo::cross(pA[0] - C.o, pB[0] - C.o)) > 0) {
r = (pA[0] - C.o).angle();
} else {
r = (pB[0] - C.o).angle();
}
if (geo::sgn(r, l) < 0) {
r += 2 * geo::pi;
}
auto calc = [&](double x) {
auto P = C.o + geo::point(C.r, 0).rotate(x);
return geo::distance(A, P) + geo::distance(B, P);
};
for (int i = 0; i < 60; ++i) {
double mid = (l + r) / 2;
if (calc(mid) > calc(mid + 1e-6)) {
l = mid;
} else {
r = mid;
}
}
std::cout << calc(l) << "\n";
}
}
详细
Test #1:
score: 100
Accepted
time: 2ms
memory: 4060kb
input:
3 0 0 2 2 1 1 1 0 0 2 2 1 0 1 0 0 2 2 1 -1 1
output:
3.571 2.927 3.116
result:
ok 3 tokens
Test #2:
score: -100
Wrong Answer
time: 651ms
memory: 4324kb
input:
100000 -9 -2 10 -3 -5 1 1 -7 0 -5 5 4 -8 10 6 -7 -2 -4 0 10 1 -5 -4 9 3 2 -10 9 10 3 1 -10 -10 -5 7 0 4 4 -1 2 6 2 -8 -10 4 -2 -1 4 3 2 8 4 10 -4 -9 4 8 0 -4 -10 8 -2 1 8 -4 -2 9 2 -3 3 -10 6 -4 1 6 2 8 -6 -7 -10 -4 1 -6 7 4 9 -1 9 -1 4 5 0 -7 4 1 10 -3 7 5 4 1 6 8 -6 1 7 8 -3 -9 -7 -1 5 -5 -2 -8 9 ...
output:
19.764 10.267 30.231 15.704 21.568 7.086 18.779 30.648 15.732 16.598 11.180 5.102 5.000 8.957 22.348 20.509 11.755 12.130 25.936 18.512 26.847 17.582 22.441 19.312 27.234 23.249 17.102 17.045 21.845 20.463 11.735 5.657 17.511 28.328 11.520 10.298 14.765 26.516 23.500 23.901 29.973 23.523 15.324 31.3...
result:
wrong answer 634th words differ - expected: '10.000', found: '65.582'