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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
#454900#7730. Convex CheckerNephrennWA 34ms8872kbC++205.2kb2024-06-25 16:28:362024-06-25 16:28:38

Judging History

你现在查看的是最新测评结果

  • [2024-07-04 19:27:17]
  • hack成功,自动添加数据
  • (/hack/727)
  • [2024-07-04 19:17:30]
  • hack成功,自动添加数据
  • (/hack/726)
  • [2024-06-25 16:28:38]
  • 评测
  • 测评结果:WA
  • 用时:34ms
  • 内存:8872kb
  • [2024-06-25 16:28:36]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;

const int MAXN = 1e2 + 10;
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3f;

random_device seed;
mt19937 rnd(seed());
mt19937_64 rnd_64(seed());

const double eps = 1e-8;

int sgn(const double &x) {
    return x < -eps ? -1 : (x > eps ? 1 : 0);
}

double sqr(const double &x) {
    return x * x;
}

struct Point {
    double x, y;
    Point operator * (const double &k) {
        return {x * k, y * k};
    }
    Point operator / (const double &k) {
        return {x / k, y / k};
    }
    Point operator + (const Point &a) {
        return {x + a.x, y + a.y};
    }
    Point operator - (const Point &a) {
        return {x - a.x, y - a.y};
    }
    bool operator < (const Point &a) {
        // return y == a.y ? x < a.x : y < a.y;
        return x == a.x ? y < a.y : x < a.x;
    }
    double len() {
        return sqrt(x * x + y * y);
    }
};

istream &operator >> (istream &is, Point &p) {
    is >> p.x >> p.y;
    return is;
}

bool operator < (const Point &a, const Point &b) {
    return a.x == b.x ? a.y < b.y : a.x < b.x;
}

bool operator == (const Point &a, const Point &b) {
    return a.x == b.x && a.y == b.y;
}

double dis(const Point &a, const Point &b) {
    return sqrt(sqr(a.x - b.x) + sqr(a.y - b.y));
}

double det(const Point &a, const Point &b) {
    return a.x * b.y - b.x * a.y;
}
double det(const Point &a, const Point &b, const Point &c) {
    return (a.x - b.x) * (c.y - b.y) - (a.y - b.y) * (c.x - b.x);
}

double dot(const Point &a, const Point &b) {
    return a.x * b.x + a.y * b.y;
}
double dot(const Point &a, const Point &b, const Point &c) {
    return (a.x - b.x) * (c.x - b.x) + (a.y - b.y) * (c.y - b.y);
}

struct Line {
    Point s, t;
};

bool point_on_segment(Point &a, Line &l) {
    return sgn(det(l.s - a, a - l.t)) == 0 && sgn(dot(l.s - a, a - l.t)) >= 0;
}

bool two_side(Point &a, Point &b, Line &c) {
    return sgn(det(a - c.s, c.t - c.s)) * sgn(det(b - c.s, c.t - c.s)) < 0;
}

bool inter_judge(Line &a, Line &b) {
    if(point_on_segment(b.s, a) || point_on_segment(b.t, a) || point_on_segment(a.s, b) || point_on_segment(a.t, b)) {
        return true;
    }
    return two_side(a.s, a.t, b) && two_side(b.s, b.t, a);
}

Point line_intersect(Line &a, Line &b) {
    double u = det(a.t - a.s, b.s - a.s);
    double v = -det(a.t - a.s, b.t - a.s);
    return (b.s * v + b.t * u) / (v + u);
}

double point_to_line(Point &p, Line &l) {
    return abs(det(l.t - l.s, p - l.s)) / dis(l.s, l.t);
}

double point_to_segment(Point &p, Line &l) {
    if(sgn(dot(l.s - p, l.t - l.s)) * sgn(dot(l.t - p, l.t - l.s)) <= 0) {
        return point_to_line(p, l);
    }
    return min(dis(p, l.s), dis(p, l.t));
}

double area(vector<Point> &a) {
    double res = 0;
    for(int i = 0; i < a.size(); ++i) {
        int j = (i + 1) % a.size();
        res += det(a[i], a[j]);
    }
    return res / 2.0;
}

bool turn_left(Point &a, Point &b, Point &c) {
    return sgn(det(b - a, c - a)) > 0;
}

bool same_dir(Line &a, Line &b) {
    return sgn(det(b.t - b.s, a.t - a.s)) == 0 && sgn(dot(b.t - b.s, a.t - a.s)) > 0;
}

vector<Point> convex_hull_Graham(vector<Point> a) {
    if(a.size() <= 2) return {}; // 或 return a;
    Point base = *min_element(a.begin(), a.end());
    sort(a.begin(), a.end(), [&](auto u, auto v) {
        int s = sgn(det(u - base, v - base));
        if(s) return s > 0;
        else return sgn(dis(u, base) - dis(v, base)) < 0;
    });
    
    vector<Point> res;
    for(auto i : a) {
        while(res.size() > 1 && !turn_left(res[res.size() - 2], res[res.size() - 1], i)) {
            res.pop_back();
        }
        res.push_back(i);
    }
    return res;
}

vector<Point> convex_hull_Andrew(vector<Point> a) {
    if(a.size() <= 2) return {}; // 或 return a
    sort(a.begin(), a.end());
    vector<Point> res;
    for(int i = 0; i < a.size(); ++i) {
        while(res.size() > 1 && !turn_left(res[res.size() - 2], res[res.size() - 1], a[i])) {
            res.pop_back();
        }
        res.push_back(a[i]);
    }
    int fix = res.size();
    for(int i = a.size() - 2; i >= 0; --i) {
        while(res.size() > fix && !turn_left(res[res.size() - 2], res[res.size() - 1], a[i])) {
            res.pop_back();
        }
        res.push_back(a[i]);
    }
    res.pop_back();
    return res;
}

void solve () {
    int n;
    cin >> n;
    vector<Point> p(n);
    for(int i = 0; i < n; ++i) cin >> p[i];
    p.push_back(p[0]);
    p.push_back(p[1]);

    double sum = 0;
    for(int i = 0; i < n; ++i) {
        int j = i + 1, k = i + 2;
        Point v1 = p[j] - p[i], v2 = p[k] - p[j];
        if(sgn(det(v1, v2)) == 0) {
            cout << "No\n";
            return;
        }
        sum += acos(dot(v1, v2) / v1.len() / v2.len());
    }
    if(sgn(sum - 2 * acos(-1)) != 0) cout << "No\n";
    else cout << "Yes\n";
}

int main () {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    int Task = 1;
    // cin >> Task;
    while (Task--) {
        solve();
    }

    return 0;
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 4140kb

input:

3
0 0
1 0
0 1

output:

Yes

result:

ok answer is YES

Test #2:

score: 0
Accepted
time: 0ms
memory: 4148kb

input:

4
0 0
0 1
1 1
1 0

output:

Yes

result:

ok answer is YES

Test #3:

score: 0
Accepted
time: 0ms
memory: 4136kb

input:

4
0 0
0 3
1 2
1 1

output:

Yes

result:

ok answer is YES

Test #4:

score: 0
Accepted
time: 0ms
memory: 3876kb

input:

3
0 0
0 0
0 0

output:

No

result:

ok answer is NO

Test #5:

score: 0
Accepted
time: 0ms
memory: 4020kb

input:

5
1 0
4 1
0 1
2 0
3 2

output:

No

result:

ok answer is NO

Test #6:

score: 0
Accepted
time: 0ms
memory: 4144kb

input:

5
0 0
1000000000 0
1000000000 500000000
1000000000 1000000000
0 1000000000

output:

No

result:

ok answer is NO

Test #7:

score: 0
Accepted
time: 0ms
memory: 3920kb

input:

5
0 0
1000000000 0
1000000000 499999999
1000000000 1000000000
0 1000000000

output:

No

result:

ok answer is NO

Test #8:

score: 0
Accepted
time: 0ms
memory: 4208kb

input:

5
0 0
999999999 0
1000000000 50000000
999999999 1000000000
0 1000000000

output:

Yes

result:

ok answer is YES

Test #9:

score: 0
Accepted
time: 31ms
memory: 8872kb

input:

128312
5578014 410408218
5585076 410404717
5588011 410403262
5588473 410403033
5589740 410402405
5593295 410400643
5593751 410400417
5597248 410398684
5598935 410397848
5600618 410397014
5605185 410394751
5610514 410392111
5614281 410390245
5617263 410388768
5621142 410386847
5630840 410382045
56310...

output:

Yes

result:

ok answer is YES

Test #10:

score: -100
Wrong Answer
time: 34ms
memory: 8224kb

input:

128086
149550602 509469827
149551059 509465022
149551336 509462107
149551964 509455497
149552572 509449094
149553350 509440895
149553656 509437667
149554161 509432339
149554254 509431357
149554545 509428284
149555017 509423299
149555366 509419611
149555842 509414580
149556382 509408867
149556564 509...

output:

No

result:

wrong answer expected YES, found NO