Submission #348117

#	Time	Username	Problem	Language	Result	Execution time	Memory
348117		jesus_coconut	Fence (CEOI08_fence)	C++17	40 / 100	1 ms	364 KiB

fence

#include <bits/stdc++.h>
#define all(a) begin(a), end(a)
#define x first
#define y second
using namespace std;



bool cw(pair<int, int> a, pair<int, int> b, pair<int, int> c) {
    return a.x*(b.y-c.y)+b.x*(c.y-a.y)+c.x*(a.y-b.y) < 0;
}

bool ccw(pair<int, int> a, pair<int, int> b, pair<int, int> c) {
    return a.x*(b.y-c.y)+b.x*(c.y-a.y)+c.x*(a.y-b.y) > 0;
}

void hull(vector<pair<int, int>>& a) {
    if (a.size() == 1)
        return;

    sort(a.begin(), a.end());
    pair<int, int> p1 = a[0], p2 = a.back();
    vector<pair<int, int>> up, down;
    up.push_back(p1);
    down.push_back(p1);
    for (int i = 1; i < (int)a.size(); i++) {
        if (i == a.size() - 1 || cw(p1, a[i], p2)) {
            while (up.size() >= 2 && !cw(up[up.size()-2], up[up.size()-1], a[i]))
                up.pop_back();
            up.push_back(a[i]);
        }
        if (i == a.size() - 1 || ccw(p1, a[i], p2)) {
            while(down.size() >= 2 && !ccw(down[down.size()-2], down[down.size()-1], a[i]))
                down.pop_back();
            down.push_back(a[i]);
        }
    }

    a = up;
    for (int i = down.size() - 2; i > 0; i--)
        a.push_back(down[i]);
}

vector<pair<int, int>> v;

bool inside(pair<int, int> p) {
    for (int i = 0; i < (int)v.size(); ++i) {
        if (ccw(p, v[i], v[(i + 1) % v.size()])) {
            return false;
        }
    }
    return true;
}

int const N = 110;

bitset<N> bio;

int mat[N][N];

int shortest_cycle() {
    int sol = 1e9;
    int n = v.size();
    for(int k = 0; k < n; ++k)
        for(int i = 0; i < n; ++i)
            for(int j = 0; j < n; ++j)
                if(mat[i][j] > mat[i][k] + mat[k][j])
                    mat[i][j] = mat[i][k] + mat[k][j];
    for(int i = 0; i < n; ++i)
        sol = min(sol, mat[i][i]);
    return sol;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m;
    cin >> n >> m;
    v.resize(n);
    for (auto &[a, b] : v) cin >> a >> b;
    hull(v);
    vector<pair<int, int>> t;
    for (int i = 0; i < m; ++i) {
        pair<int, int> p;
        cin >> p.x >> p.y;
        if (inside(p)) {
            t.push_back(p);
        }
    }
    if (t.size() == 0) {
        cout << 111ll * m << '\n';
        return 0;
    }
    memset(mat, 0x3f, sizeof mat);
    for (int i = 0; i < v.size(); ++i) {
        for (int k = 0; k < v.size(); ++k) {
            if (i == k) continue;
            bool b = true;
            for (int j = 0; j < (int)t.size(); ++j) {
                if (ccw(v[i], v[k], t[j])) {
                    b = false;
                    break;
                }
            }
            if (b) {
                mat[i][k] = 1;
            }
        }
    }
    cout << 20ll * shortest_cycle() + 111ll * (m - t.size());

    return 0;
}

Compilation message (stderr)

fence.cpp: In function 'void hull(std::vector<std::pair<int, int> >&)':
fence.cpp:27:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |         if (i == a.size() - 1 || cw(p1, a[i], p2)) {
      |             ~~^~~~~~~~~~~~~~~
fence.cpp:32:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         if (i == a.size() - 1 || ccw(p1, a[i], p2)) {
      |             ~~^~~~~~~~~~~~~~~
fence.cpp: In function 'int main()':
fence.cpp:96:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   96 |     for (int i = 0; i < v.size(); ++i) {
      |                     ~~^~~~~~~~~~
fence.cpp:97:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |         for (int k = 0; k < v.size(); ++k) {
      |                         ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10