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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#31967#2838. 2D GeometryVingying0#WA 2ms3784kbC++171.3kb2022-05-14 12:56:262022-05-14 12:56:27

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2022-05-14 12:56:27]
  • 评测
  • 测评结果:WA
  • 用时:2ms
  • 内存:3784kb
  • [2022-05-14 12:56:26]
  • 提交

answer

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

const int N = 2E5 + 50;
int n;
using db = long long;
using ll = long long;
struct Point
{
    db x, y;
    Point() = default;
    Point(db x, db y) : x(x), y(y) {}
    db operator^(const Point &t) const
    {
        return x * t.y - y * t.x;
    }
    Point operator-(const Point &t) const
    {
        return Point(x - t.x, y - t.y);
    }
} p[N];

int rd(int l, int r)
{
    return 1ll * rand() % r * rand() % r + 1;
}

int main()
{
    srand(time(NULL));
    while (scanf("%d", &n) == 1)
    {
        for (int i = 1; i <= n; i++)
        {
            int x, y;
            scanf("%d%d", &x, &y);
            p[i].x = x, p[i].y = y;
        }
        if (n <= 2) {
            printf("%d\n", n);
            continue;
        }
        ll ans = 0, tmp;
        for (int cnt = 0; cnt < 10; ++cnt)
        {
            int x = rd(1, n), y = rd(1, n);
            while (x == y)
                y = rd(1, n);
            long long sum = 0;
            for (int i = 1; i <= n; ++i)
                sum += ((p[x] - p[i]) ^ (p[y] - p[i])) == 0;
            if (sum * 3 >= 2 * n)
            {
                ans = max(ans, sum - 2 * (n - sum));
            }
        }
        printf("%lld\n", ans);
    }
    return 0;
}

Details

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Test #1:

score: 100
Accepted
time: 1ms
memory: 3692kb

input:

3
0 0
0 1
0 2
3
0 0
0 1
1 0
6
0 0
0 1
0 2
0 3
1 1
1 2

output:

3
0
0

result:

ok 3 lines

Test #2:

score: -100
Wrong Answer
time: 2ms
memory: 3784kb

input:

1
0 0
2
0 0
1 1
3
0 0
0 1
0 2
3
0 0
0 1
1 0
4
3 0
0 2
3 3
3 1
4
2 3
1 1
0 3
0 2
4
0 0
0 3
0 2
0 1
5
8 6
9 2
2 3
7 4
1 5
5
2 2
4 2
6 2
7 2
0 4
5
3 7
5 4
4 4
9 4
9 9
5
5 4
5 9
5 5
4 3
1 0
5
3 2
1 2
7 2
6 2
5 2
6
7 2
7 9
0 3
8 8
4 4
3 8
6
2 8
2 5
3 5
3 8
2 0
0 2
6
2 3
8 4
2 9
2 2
2 6
4 9
6
2 1
7 6
6 5
...

output:

1
2
3
0
1
0
4
0
2
0
0
5
0
0
0
0
0
0
0
3
0
6

result:

wrong answer 6th lines differ - expected: '1', found: '0'