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 |
---|---|---|---|---|---|---|---|---|---|
#91266 | #5106. Islands from the Sky | _skb_ | WA | 7ms | 3828kb | C++17 | 7.2kb | 2023-03-28 05:29:03 | 2023-03-28 05:29:04 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
using u64 = unsigned long long;
struct debug {
#define contPrint { *this << "["; \
int f = 0; for(auto it : x) { *this << (f?", ":""); *this << it; f = 1;} \
*this << "]"; return *this;}
~debug(){cerr << endl;}
template<class c> debug& operator<<(c x) {cerr << x; return *this;}
template<class c, class d>
debug& operator<<(pair<c, d> x) {*this << "(" << x.first << ", " << x.second << ")";
return *this;}
template<class c> debug& operator<<(vector<c> x) contPrint;
#undef contPrint
};
#define dbg(x) "[" << #x << ": " << x << "] "
#define Wa() cerr << "[LINE: " << __LINE__ << "] -> "; debug() <<
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL);
using ld = long double;
const ld PI = acosl(-1.0);
const ld EPS = 1e-12;
struct Point {
ld x, y, z;
Point() {}
Point(ld _x, ld _y) : x(_x), y(_y) {}
Point(ld _x, ld _y, ld _z) : x(_x), y(_y), z(_z) {}
bool operator<(const Point& other) const {
return (abs(x - other.x) > EPS && x < other.x) || (abs(x - other.x) < EPS && y < other.y);
}
};
struct Line {
ld a, b, c;
Point p1, p2;
ld theta;
Line() {}
Line(ld _a, ld _b, ld _c) : a(_a), b(_b), c(_c) {calc_theta();}
Line(Point _p1, Point _p2) : p1(_p1), p2(_p2) {
ld del_x = p1.x - p2.x;
ld del_y = p1.y - p2.y;
a = del_y;
b = -del_x;
c = -p1.x * del_y + p1.y * del_x;
calc_theta();
}
void calc_theta() {
if(b == 0) {
theta = PI / 2;
} else {
theta = atanl(-a / b);
}
}
Line perpendicular(Point p) {
ld pa, pb, pc;
pa = b;
pb = -a;
pc = -pa * p.x - pb * p.y;
return Line(pa, pb, pc);
}
vector<Point> getPoints(Point p, ld d) {
vector<Point> ret;
ret.push_back(Point(p.x + d * cosl(theta), p.y + d * sinl(theta)));
ret.push_back(Point(p.x + d * cosl(theta + PI), p.y + d * sinl(theta + PI)));
return ret;
}
};
int orientation(Point a, Point b, Point c) {
double v = a.x*(b.y-c.y)+b.x*(c.y-a.y)+c.x*(a.y-b.y);
if (v < 0) return -1; // clockwise
if (v > 0) return +1; // counter-clockwise
return 0;
}
bool cw(Point a, Point b, Point c, bool include_collinear) {
int o = orientation(a, b, c);
return o < 0 || (include_collinear && o == 0);
}
bool ccw(Point a, Point b, Point c, bool include_collinear) {
int o = orientation(a, b, c);
return o > 0 || (include_collinear && o == 0);
}
void convex_hull(vector<Point>& a, bool include_collinear = false) {
if (a.size() == 1)
return;
sort(a.begin(), a.end(), [](Point a, Point b) {
return make_pair(a.x, a.y) < make_pair(b.x, b.y);
});
Point p1 = a[0], p2 = a.back();
vector<Point> up, down;
up.push_back(p1);
down.push_back(p1);
for (int i = 1; i < (int)a.size(); i++) {
if (i == a.size() - 1 || cw(p1, a[i], p2, include_collinear)) {
while (up.size() >= 2 && !cw(up[up.size()-2], up[up.size()-1], a[i], include_collinear))
up.pop_back();
up.push_back(a[i]);
}
if (i == a.size() - 1 || ccw(p1, a[i], p2, include_collinear)) {
while (down.size() >= 2 && !ccw(down[down.size()-2], down[down.size()-1], a[i], include_collinear))
down.pop_back();
down.push_back(a[i]);
}
}
if (include_collinear && up.size() == a.size()) {
reverse(a.begin(), a.end());
return;
}
a.clear();
for (int i = 0; i < (int)up.size(); i++)
a.push_back(up[i]);
for (int i = down.size() - 2; i > 0; i--)
a.push_back(down[i]);
}
int main()
{
// auto it = Line(1, 0, 0).getPoints(Point(0, 0), sqrt(2));
// Wa() dbg(it[0].x) dbg(it[0].y) dbg(it[1].x) dbg(it[1].y);
int n, m;
scanf("%d %d", &n, &m);
vector<vector<Point>> islands(n);
for(int i = 0; i < n; i++) {
int p;
scanf("%d", &p);
while(p--) {
ld x, y;
scanf("%Lf %Lf", &x, &y);
islands[i].push_back(Point(x, y));
}
}
vector<pair<Point, Point>> routes(m);
vector<pair<Line, Line>> p_lines(m);
for(int i = 0; i < m; i++) {
ld x, y, z;
scanf("%Lf %Lf %Lf", &x, &y, &z);
routes[i].first = Point(x, y, z);
scanf("%Lf %Lf %Lf", &x, &y, &z);
routes[i].second = Point(x, y, z);
p_lines[i].first = Line(routes[i].first, routes[i].second).perpendicular(routes[i].first);
p_lines[i].second = Line(routes[i].first, routes[i].second).perpendicular(routes[i].second);
}
auto get_area = [] (vector<Point> v) {
ld ret = 0;
v.push_back(v[0]);
for(int i = 0; i < (int)v.size()-1; i++) {
ret += v[i].x * v[i+1].y - v[i].y * v[i+1].x;
// Wa() dbg(i) dbg(v[i].x) dbg(v[i].y) dbg(ret);
}
return abs(ret);
};
ld lo = 0;
ld hi = PI / 2;
int step = 60;
while(step--) {
ld mid = (lo + hi) / 2;
vector<vector<Point>> rect(m);
vector<ld> area(m);
for(int i = 0; i < m; i++) {
vector<Point> v1 = p_lines[i].first.getPoints(routes[i].first, routes[i].first.z * tanl(mid));
vector<Point> v2 = p_lines[i].second.getPoints(routes[i].second, routes[i].second.z * tanl(mid));
v1.push_back(v2[0]);
v1.push_back(v2[1]);
sort(v1.begin(), v1.end());
convex_hull(v1);
// sort(v1.begin() + 1, v1.end(), [&] (Point a, Point b) {
// ld theta1 = abs(v1[0].x - a.x) < EPS ? PI / 2 : atanl((v1[0].y - a.y) / (v1[0].x - a.x));
// ld theta2 = abs(v1[0].x - b.x) < EPS ? PI / 2 : atanl((v1[0].y - b.y) / (v1[0].x - b.x));
// // Wa() dbg(a.x) dbg(a.y) dbg(theta1) dbg(b.x) dbg(b.y) dbg(theta2);
// return abs(theta1 - theta2) > EPS && theta1 < theta2;
// });
area[i] = get_area(v1);
rect[i] = v1;
// Wa() dbg(area[i]) dbg(v1[0].x) dbg(v1[0].y) dbg(mid);
}
int cnt = 0;
for(int i = 0; i < n; i++) {
for(int j = 0; j < m; j++) {
bool inside = true;
for(auto p : islands[i]) {
ld cur_area = 0;
for(int k = 0; k < 4; k++) {
vector<Point> temp = {rect[j][k], rect[j][(k+1) % 4], p};
cur_area += get_area(temp);
}
if(cur_area - area[j] > EPS) {
inside = false;
break;
}
}
if(inside) {
cnt++;
break;
}
}
}
if(cnt == n) {
hi = mid;
} else {
lo = mid;
}
}
if(abs(PI / 2 - hi) < EPS) {
puts("impossible");
} else {
printf("%.9Lf\n", lo * 180 / PI);
}
}
详细
Test #1:
score: 100
Accepted
time: 2ms
memory: 3756kb
input:
1 1 3 -5 0 5 0 0 5 -10 10 10 10 10 10
output:
45.000000000
result:
ok
Test #2:
score: 0
Accepted
time: 2ms
memory: 3724kb
input:
1 1 3 -5 0 5 0 0 5 -10 0 10 10 0 10
output:
26.565051177
result:
ok
Test #3:
score: 0
Accepted
time: 2ms
memory: 3756kb
input:
1 1 3 -5 0 5 0 0 5 0 10 10 10 0 10
output:
46.686143342
result:
ok
Test #4:
score: 0
Accepted
time: 2ms
memory: 3828kb
input:
1 1 3 -5 0 5 0 0 5 0 10 5 10 0 10
output:
59.491041134
result:
ok
Test #5:
score: 0
Accepted
time: 2ms
memory: 3660kb
input:
1 1 3 -5 0 5 0 0 5 0 10 20 -10 0 10
output:
31.219698447
result:
ok
Test #6:
score: 0
Accepted
time: 0ms
memory: 3680kb
input:
1 3 3 -5 0 5 0 0 5 -10 0 25 10 0 20 -5 10 10 10 -5 20 -4 1 100 5 10 100
output:
12.528807709
result:
ok
Test #7:
score: 0
Accepted
time: 1ms
memory: 3808kb
input:
1 2 4 0 0 20 0 20 40 0 40 -10 30 30 30 30 30 -10 10 30 30 10 30
output:
45.000000000
result:
ok
Test #8:
score: 0
Accepted
time: 2ms
memory: 3636kb
input:
1 4 4 0 0 20 0 20 40 0 40 -10 30 30 30 30 30 -10 20 30 30 20 30 -10 10 30 30 10 30 10 -10 30 10 50 30
output:
18.434948823
result:
ok
Test #9:
score: 0
Accepted
time: 2ms
memory: 3680kb
input:
1 2 4 0 0 40 0 40 40 0 40 10 10 10 20 20 20 30 10 10 10 30 20
output:
impossible
result:
ok
Test #10:
score: 0
Accepted
time: 0ms
memory: 3564kb
input:
1 3 4 0 0 20 0 20 40 0 40 -10 30 30 15 30 30 5 30 30 30 30 30 1 50 30 21 50 30
output:
impossible
result:
ok
Test #11:
score: 0
Accepted
time: 2ms
memory: 3676kb
input:
1 1 4 0 0 40 0 40 40 0 40 -100 -100 20 100 100 10
output:
63.665752153
result:
ok
Test #12:
score: 0
Accepted
time: 2ms
memory: 3760kb
input:
1 4 4 -10 -10 10 -10 10 10 -10 10 -100 0 10 100 0 10 0 100 10 0 -100 10 50 50 15 -50 -50 15 -50 50 15 50 -50 15
output:
43.313856658
result:
ok
Test #13:
score: -100
Wrong Answer
time: 7ms
memory: 3640kb
input:
1 100 100 822286 0 856789 53904 986567 124632 629039 119995 732157 187986 691605 224716 728650 288493 591087 278144 801573 440668 425257 269876 614456 446428 424157 350893 645680 606334 406524 432904 545628 659551 359831 495265 367048 578376 251435 457360 319990 680014 336526 849968 214009 658652 23...
output:
impossible
result:
wrong answer