Submission #1065744

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065744		deera	Soccer Stadium (IOI23_soccer)	C++17	6 / 100	203 ms	43604 KiB

soccer

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

struct Pos {
    int x, y;
    Pos(int x, int y) : x(x), y(y) {}
};

int biggest_stadium(int N, vector<vector<int>> F) {
    vector<Pos> trees;
    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) {
        if (F[i][j] == 1) trees.push_back({i, j});
    }

    for (auto tree : trees) {
        cerr << tree.x << " " << tree.y << endl;
    }

    if (trees.size() == 0) return N * N;
    if (trees.size() == 1) {
        int x = trees[0].x, y = trees[0].y;

        int n = N - 1;
        int a = (abs(x - 0) + 1) * (abs(y - 0) + 1);
        int b = (abs(x - 0) + 1) * (abs(y - n) + 1);
        int c = (abs(x - n) + 1) * (abs(y - 0) + 1);
        int d = (abs(x - n) + 1) * (abs(y - n) + 1);


        return N * N - min({a, b, c, d});
    }

    // for 25% of marks
    bool BORDER[2001][2001] = {0};
    queue<Pos> q;
    set<pair<int, int>> once;

    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) {
        if (F[i][j] == 1 && (i == 0 || i == N - 1 || j == 0 || j == N - 1)) {
            once.insert({i, j});
        }
    }

    for (int i: {0, N - 1}) for (int j: {0, N - 1}) if (F[i][j]) {
        q.push({i, j});
        BORDER[i][j] = true;
    }


    while (!q.empty()) {
        Pos p = q.front(); q.pop();
        int x = p.x, y = p.y;

        for (int i: {-1, 0, 1}) for (int j: {-1, 0, 1}) {
            if (i == 0 && j == 0) continue;
            if (i != 0 && j != 0) continue;
            if (x + i < 0 || x + i >= N || y + j < 0 || y + j >= N) continue;
            
            if (F[x + i][y + j] && !BORDER[x + i][y + j]) {
                if (once.find({x + i, y + j}) != once.end()) {
                    q.push({x + i, y + j});
                    BORDER[x + i][y + j] = true;
                } else {
                    once.insert({x + i, y + j});
                }
            }
        }
    }



    int all = true;
    for (Pos t: trees)
        if (!BORDER[t.x][t.y]) {all = false; break;};

    if (all) return N * N - trees.size();
    else return 0;
}

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 0 / 8
• Subtask 3: 0 / 22
• Subtask 4: 0 / 18
• Subtask 5: 0 / 16
• Subtask 6: 0 / 30