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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
#722612#9576. Ordainer of Inexorable Judgmentucup-team2179WA 0ms4208kbC++204.0kb2024-11-07 19:39:112024-11-07 19:39:13

Judging History

你现在查看的是最新测评结果

  • [2024-12-23 14:23:26]
  • hack成功,自动添加数据
  • (/hack/1303)
  • [2024-12-06 11:32:56]
  • hack成功,自动添加数据
  • (/hack/1271)
  • [2024-11-14 21:58:28]
  • hack成功,自动添加数据
  • (/hack/1181)
  • [2024-11-07 19:39:13]
  • 评测
  • 测评结果:WA
  • 用时:0ms
  • 内存:4208kb
  • [2024-11-07 19:39:11]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;

const double eps = 1e-8;      // 根据题目精度要求进行修改
const double PI = acos(-1.0); // pai, 3.1415916....

int sgn(double x)
{ // 进行判断, 提高精度
    if (fabs(x) < eps)
        return 0;          // x == 0, 精度范围内的近似相等
    return x > 0 ? 1 : -1; // 返回正负
}

// 点和向量<---------------------------------------------->
// Need: sgn()
typedef struct Point
{
    double x, y;
    Point(double x = 0, double y = 0) : x(x), y(y) {} // 构造函数, 初始值为 0

    // 重载运算符
    // 点 - 点 = 向量(向量AB = B - A)
    Point operator-(const Point &B) const { return Point(x - B.x, y - B.y); }

    // 点 + 点 = 点, 点 + 向量 = 向量, 向量 + 向量 = 向量
    Point operator+(const Point &B) const { return Point(x + B.x, y + B.y); }

    // 向量 × 向量 (叉积)
    double operator^(const Point &B) const { return x * B.y - y * B.x; }

    // 向量 · 向量 (点积)
    double operator*(const Point &B) const { return x * B.x + y * B.y; }
} Vector;
struct Circle
{
    Point c;
    double r;
    Circle(Point c = Point(), double r = 0) : c(c), r(r) {}
};

double len(Vector A) { return sqrt(A * A); }
Vector Rotate(Vector A, double b)
{
    Vector B(sin(b), cos(b));
    return Vector(A ^ B, A * B);
}
// 点到圆的切线
// 过点p到圆c的切线,v[i]是第i条切线
vector<Vector> get_tangents(Point p, Circle C)
{
    Vector u = C.c - p;
    double dist = len(u);
    if (dist < C.r)
        return {}; // 点在内部,没有切线
    else if (sgn(dist - C.r) == 0)
    { // p在圆上,只有一条切线
        return {Rotate(u, PI / 2)};
    }
    else
    { // 否则是两条切线
        double ang = asin(C.r / dist);
        return {Rotate(u, -ang), Rotate(u, +ang)};
    }
}
// 判断点在直线的哪边
// Need: (-, ^), sgn()
// 点在直线上, 返回 0 (三点共线)
// 点在直线的逆时针方向, 返回 1
// 点在直线的顺时针方向, 返回 -1
// 点 a, b (向量ab) 所在的直线和点 c
// 使用的时候要注意 a 和 b 的顺序, 有时顺序不同, 结果不同
int Cross(Point a, Point b, Point c) { return sgn((b - a) ^ (c - a)); }

Point a[105];
int n, x, y, d, t;
Circle c;

double col(int op)
{
    for (int i = 1; i <= n; i++)
    {
        vector<Vector> t = get_tangents(a[i], c);
        Point q;
        for (auto [x, y]: t) 
        {
            x += a[i].x, y += a[i].y;
            if (Cross({x, y}, a[i], {0, 0}) == op) q = {x, y};
        }
        int f = 1;
        for (int j = 1; j <= n; j++)
        {
            if (i == j) continue;
            if (Cross(q, a[i], a[j]) == op) 
            {
                f = 0;
                break;
            }
        }
        if (f)
        {
            double jd = atan2(a[i].y - q.y, a[i].x - q.x);
            return jd;
        }
    }
    return 0.0;
}
void solve()
{
    cin >> n >> x >> y >> d >> t;
    c = {{0, 0}, (double)d};
    double cs = atan2(y, x);

    for (int i = 1; i <= n; i++) cin >> a[i].x >> a[i].y;
    // 开始受到伤害
    double s = col(-1), e = col(1);
    if (s < 0) s += 2 * PI;
    if (e < 0) e += 2 * PI;
    if (cs < 0) cs += 2 * PI;
    if (s > e) e += 2 * PI;
    double zh = (int)(t / (2 * PI));
    double sh = t - (2 * PI) * zh;
    double ans = zh * (e - s);
    cout << ans << '\n';
    if (cs < s)  ans += max(0.0, min(e, cs + sh) - s);
    else if (cs < e) ans += max(0.0, min(e, cs + sh) - cs);
    else 
    {
        s += 2 * PI, e += 2 * PI;
        ans += max(0.0, min(e, cs + sh) - s);
    }
    cout << fixed << setprecision(10) << ans << '\n';
}
signed main()
{
    // freopen("D:\\3022244240\\vscode\\txt\\in.txt", "r", stdin);
    // freopen("D:\\3022244240\\vscode\\txt\\out.txt", "w", stdout);
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int T = 1;
    // cin >> T;
    while (T--) solve();
    return 0;
}

/*

*/

詳細信息

Test #1:

score: 0
Wrong Answer
time: 0ms
memory: 4208kb

input:

3 1 0 1 1
1 2
2 1
2 2

output:

0
1.0000000000

result:

wrong answer 1st numbers differ - expected: '1.0000000', found: '0.0000000', error = '1.0000000'