Submission #1632939

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

const int Mod = 998244353, Nmax = 205;

struct Fractie
{
    int up, down;
    bool operator < (const Fractie &other) const
    {
        return up * other.down < down * other.up;
    }

    bool operator == (const Fractie &other) const
    {
        return up * other.down == down * other.up;
    }
} v[Nmax];

struct Point
{
    int x, y;
    bool operator < (const Point &other) const
    {
        if(x == other.x) return y < other.y;
        return x < other.x;
    }
} a[Nmax];

int pw[Nmax], i, n, ans, j, k;

int main()
{
  //  freopen("input", "r", stdin);

    cin >> n;
    for(i=1; i<=n; ++i) cin >> a[i].x >> a[i].y;
    sort(a+1, a+n+1);

    pw[0] = 1;
    for(i=1; i<=n; ++i)
        pw[i] = pw[i-1] * 2 % Mod;

    ans = pw[n] - n - 1;
    for(i=1; i<=n; ++i)
    {
        for(j=i+1; j<=n; ++j) v[j-i] = {a[j].y - a[i].y, a[j].x - a[i].x};
        sort(v+1, v+n-i+1);

        for(j=1; j<=n-i; ++j)
        {
            k = j;
            while(k < n-i && v[j] == v[k+1]) ++k;
            ans -= pw[k-j+1] - 1;
            if(ans < 0) ans += Mod;
            j = k;
        }
    }

    cout << ans << '\n';

    return 0;
}

Submission Info

Judge Result