Submission #348238

#	Time	Username	Problem	Language	Result	Execution time	Memory
348238		saral	Fence (CEOI08_fence)	C++14	100 / 100	6 ms	4460 KiB

fence

#include <bits/stdc++.h>

using namespace std;
#define lli long long int
const int N = 1010;
int t, n, m, a, b;
const int INF = 1e5;

vector<pair<pair<int, int>, int> > holes, trees;
vector<pair<int, int> > holesOG;

vector<int>lowHull, upHull, possApples, all;

int ccw (pair<int, int>a, pair<int, int>b, pair<int, int>c) {
    return (a.first*(b.second-c.second)+b.first*(c.second-a.second)+c.first*(a.second-b.second));
}

int dist[N][N];

void mHull () {
    sort (holes.begin(), holes.end());

    for (int i = 0; i < holes.size(); i++) {
        while (lowHull.size() > 1 && ccw (holesOG[lowHull[lowHull.size()-2]], holesOG[lowHull[lowHull.size()-1]], holes[i].first) <= 0) {
            lowHull.pop_back();
        }
        lowHull.push_back(holes[i].second);
    }

    reverse (holes.begin(), holes.end());

    for (int i = 0; i < holes.size(); i++) {
        while (upHull.size() > 1 && ccw (holesOG[upHull[upHull.size()-2]], holesOG[upHull[upHull.size()-1]], holes[i].first) <= 0) {
            upHull.pop_back();
        }
        upHull.push_back(holes[i].second);
    }

}

void checkApples () {
    for (int j = 0; j < trees.size(); j++) {
        int p1, p2;
        int l=0;
        for (int i = 0; i < lowHull.size()-1; i++) {
            p1 = lowHull[i], p2 = lowHull[i+1];
            if (ccw(holesOG[p1], holesOG[p2], trees[j].first) <= 0) {
                l=1;
                break;
            }
        }
        for (int i = 0; i < upHull.size()-1; i++) {
            p1 = upHull[i], p2 = upHull[i+1];
            if (ccw(holesOG[p1], holesOG[p2], trees[j].first) <= 0) {
                l=1;
                break;
            }
        }
        if (!l) possApples.push_back(j);
    }
return;
}

bool allIn (int x, int y) {
    int br1=0, br2=0;
    for (int i = 0; i < possApples.size(); i++) {
        if (ccw (holesOG[x], holesOG[y], trees[possApples[i]].first) <= 0) return false;
    }
    return true;
}

void checkEdges () {
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            dist[i][j]=INF;
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (i!=j && allIn(i, j)) {
                dist[i][j]=1;
            }
            else {
                dist[i][j]=INF;
            }
        }
    }
return;
}
int mini;


void floyd () {
    for (int k = 0; k < n; k++) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                dist[i][j] = min(dist[i][j], dist[i][k]+dist[k][j]);
            }
        }
    }
    mini=INF;
    for (int i = 0; i < n; i++) {
        mini = min(mini, dist[i][i]);
    }
return;
}

void solve () {
    //cout << ccw (make_pair(800, 300), make_pair(600, 700), make_pair(200, 700));
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        cin >> a >> b;
        holes.push_back(make_pair(make_pair(a, b), i));
        holesOG.push_back(make_pair(a, b));
    }
    for (int i = 0; i < m; i++) {
        cin >> a >> b;
        trees.push_back(make_pair(make_pair(a, b), i));
    }

    mHull ();

    checkApples();
    checkEdges();
    floyd();
    if (possApples.empty()) {
        cout << trees.size()*111 << endl;
        return;
    }
    cout << mini*20+(trees.size()-possApples.size())*111 << endl;
return;
}

int main () {
	solve();

return 0;
}

Compilation message (stderr)

fence.cpp: In function 'void mHull()':
fence.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int i = 0; i < holes.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~
fence.cpp:32:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for (int i = 0; i < holes.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~
fence.cpp: In function 'void checkApples()':
fence.cpp:42:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     for (int j = 0; j < trees.size(); j++) {
      |                     ~~^~~~~~~~~~~~~~
fence.cpp:45:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |         for (int i = 0; i < lowHull.size()-1; i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~
fence.cpp:52:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |         for (int i = 0; i < upHull.size()-1; i++) {
      |                         ~~^~~~~~~~~~~~~~~~~
fence.cpp: In function 'bool allIn(int, int)':
fence.cpp:66:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |     for (int i = 0; i < possApples.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~
fence.cpp:65:9: warning: unused variable 'br1' [-Wunused-variable]
   65 |     int br1=0, br2=0;
      |         ^~~
fence.cpp:65:16: warning: unused variable 'br2' [-Wunused-variable]
   65 |     int br1=0, br2=0;
      |                ^~~

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