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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
#721429#5540. City Hallzijinjun#WA 0ms3580kbC++173.7kb2024-11-07 16:05:522024-11-07 16:05:53

Judging History

你现在查看的是最新测评结果

  • [2024-11-07 16:05:53]
  • 评测
  • 测评结果:WA
  • 用时:0ms
  • 内存:3580kb
  • [2024-11-07 16:05:52]
  • 提交

answer

#include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
#include <unordered_set>
#include <functional>
#include <stack>
#include <unordered_map>
#include <map>
#include <cmath>
using namespace std;

inline int read() {
    int x = 0, f = 1;
    char c = getchar();
    while (c > '9' || c < '0')
        f = c == '-' ? -1 : 1, c = getchar();
    while (c >= '0' && c <= '9')
        x = x * 10 + c - 48, c = getchar();
    return x * f;
}
using i64 = long long;
using u64 = unsigned long long;
using pii = pair<int, int>;
using pll = pair<i64, i64>;

struct Point {
    int x, y;
    Point (int _x = 0, int _y = 0) {
        x = _x, y = _y;
    }
};
using Vector = Point;
Point operator + (Point a, Point b) {
    return Point(a.x + b.x, a.y + b.y);
}
Point operator - (Point a, Point b) {
    return Point(a.x - b.x, a.y - b.y);
}
int sgn(int x) {
    return (x > 0) - (x < 0);
}
bool operator < (Point a, Point b) {
    return sgn(a.x - b.x) < 0 || ((sgn(a.x-b.x) == 0) && sgn(a.y - b.y) < 0);
}
double Dot(Point a, Point b) {
    return a.x * b.x + a.y * b.y;
}
double Cross (Point a, Point b) {
    return a.x * b.y - a.y * b.x;
}

const int N = 1010;
Point hull[N], p[N];
int n;
int get_hull() {
    sort(p, p + n);
    int v = 0;
    for (int i = 0; i < n; ++i) {
        while (v > 1 && sgn(Cross(hull[v-1] - hull[v-2], p[i] - hull[v-1])) <= 0)
            v--;
        hull[v++] = p[i];
    }
    int j = v;
    for (int i = n - 2; i > 0; --i) {
        while (v > j && sgn(Cross(hull[v-1]-hull[v-2], p[i]-hull[v-1])) <= 0)
            --v;
        hull[v++] = p[i];
    }
    if (n > 1) v--;
    return v;
}

int get_dimension(const Vector &x, const Vector &y) {
    int dot = sgn(Dot(x, y));
    int cross = sgn(Cross(x, y));
    if (cross == 0 && dot == 0)
        return 0;
    if (cross == 0 && dot > 0)
        return 1;
    if (cross > 0 && dot > 0)
        return 2;
    if (cross > 0 && dot < 0)
        return 3;
    if (cross == 0 && dot < 0)
        return 4;
    if (cross < 0 && dot < 0)
        return 5;
    return 6; // cross < 0, dot > 0
}

struct cmp {
    Point p;
    Vector v;
    cmp(const Point &p0, const Vector &v0) {
        p = p0;
        v = v0;
    }
    bool operator()(const Point &a, const Point &b) {
        int da = get_dimension(v, a - p);
        int db = get_dimension(v, b - p);
        if (da != db)
            return da < db;
        return sgn(Cross(a - p, b - p)) > 0;
    }
};

bool is_between(int x, int l, int r) {
    return l <= x && x <= r;
}

int main() {
    n = read();
    for (int i = 0; i < n; ++i)
        p[i].x = read(), p[i].y = read();
    int m = get_hull();
//    cout << m << " : ";
//    for (int i = 0; i <= m; ++i)
//        cout << hull[i].x <<" "<< hull[i].y<<endl;
    int ans = 0;
    for (int i = 0; i < m; i++) {
        sort(p, p + n, cmp(hull[i], hull[(i + 1) % n] - hull[i]));
        int sum = 0;
        int cnt1 = 0, cnt2 = 0, cnt3 = 0; // 下面的,中间的,上面的
        // j->hull k1->p k2->p
        int k1 = 1, k2 = 1;
        for (int j = (i + 1) % m; j != i; j = (j + 1) % m) {
            k2 = max(k2, k1 + 1);
            while (k1 < n && Cross(hull[j] - hull[i], p[k1] - hull[i]) < 0)
                k1++;
            while (k2 < n && Cross(hull[j] - hull[i], p[k2] - hull[i]) <= 0)
                k2++;
            cnt2 = k2 - k1 - 1;
            cnt1 = max(0, k1 - 1);
            cnt3 = n - k2;
            sum = (cnt1 + cnt3) * cnt2 + cnt2 * (cnt2 - 1) / 2 + cnt1 * cnt3;
            ans = max(ans, sum);
        }
    }
    cout << ans << endl;
    return 0;
}
/*
6

0 0
0 6
6 0
6 6
1 4
1 2

 */

详细

Test #1:

score: 0
Wrong Answer
time: 0ms
memory: 3580kb

input:

5 6 1 3
5 100 8 2 10
1 2
2 3
2 5
1 4
4 5
3 5

output:

2

result:

wrong answer 1st numbers differ - expected: '4.5000000', found: '2.0000000', error = '0.5555556'