Submission #1080575

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080575		shmax	Soccer Stadium (IOI23_soccer)	C++17	6 / 100	391 ms	56148 KiB

soccer

#include "soccer.h"
#include "bits/stdc++.h"

using namespace std;
using i32 = int;
#define int long long
#define len(x) (int)(x.size())
#define all(x) x.begin(), x.end()
#define inf 1000'000'000'000'000'000LL
#define bit(x, i) (((x) >> i) & 1)


template<typename T>
using vec = vector<T>;


int check(i32 n, std::vector<std::vector<i32>> F) {
    int cnt = 0;
    set<int> columns;
    set<int> rows;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cnt += F[i][j] == 0;
            if (F[i][j] == 0) {
                rows.insert(i);
                columns.insert(j);
            }
        }
    }

    vec<vec<bool>> used(n, vec<bool>(n, false));
    for (int i = 1; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (used[i][j]) continue;
            if (!F[i][j]) continue;
            if (F[i - 1][j] == 0) {
                for (int k = i; k < n; k++) {
                    if (F[k][j] == 0) return 0;
                    used[k][j] = true;
                }
            }
        }
    }
    used = vec<vec<bool>>(n, vec<bool>(n, false));
    for (int i = 0; i < n; i++) {
        for (int j = 1; j < n; j++) {
            if (used[i][j]) continue;
            if (!F[i][j]) continue;
            if (F[i][j - 1] == 0) {
                for (int k = j; k < n; k++) {
                    if (F[i][k] == 0) return 0;
                    used[i][k] = true;
                }
            }
        }
    }

    vec<vec<int>> pref(n + 1, vec<int>(n + 1, 0));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            pref[i + 1][j + 1] = pref[i][j + 1] + pref[i + 1][j] - pref[i][j] + F[i][j];
        }
    }

    auto get = [&](int i1, int j1, int i2, int j2) {
        return pref[i2 + 1][j2 + 1] - pref[i2 + 1][j1] - pref[i1][j2 + 1] + pref[i1][j1];
    };

    vec<pair<int, int>> X(n, {inf, -inf});
    vec<pair<int, int>> Y(n, {inf, -inf});
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (F[i][j]) continue;
            X[i].first = min(X[i].first, j);
            X[i].second = max(X[i].first, j);
            Y[j].first = min(Y[j].first, i);
            Y[j].second = max(Y[j].first, i);
        }
    }

    for (int i: rows) {
        for (int j: columns) {
            if (F[i][j] == 0) continue;
            int i1 = Y[j].first;
            int i2 = Y[j].second;
            int j1 = X[i].first;
            int j2 = X[i].second;
            if (get(i1, j1, i2, j2) != 0)
                return 0;
        }
    }

    return cnt;
}

i32 biggest_stadium(i32 n, std::vector<std::vector<i32>> F) {

    if (check(n, F) != 0) return check(n, F);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (F[i][j] == 1) {
                int best = 0;
                best = max(best, n * n - (i + 1) * (j + 1));
                best = max(best, n * n - (i + 1) * (n - j));
                best = max(best, n * n - (n - i) * (j + 1));
                best = max(best, n * n - (n - i) * (n - j));
                return best;
            }
        }
    }
    
}

Compilation message (stderr)

soccer.cpp: In function 'i32 biggest_stadium(i32, std::vector<std::vector<int> >)':
soccer.cpp:112:1: warning: control reaches end of non-void function [-Wreturn-type]
  112 | }
      | ^

• 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