Submission #840009

#	Time	Username	Problem	Language	Result	Execution time	Memory
840009		olnyfcxwps	Soccer Stadium (IOI23_soccer)	C++17	0 / 100	19 ms	4376 KiB

soccer

#include <iostream>
#include <vector>
using namespace std;

const int N = 30;
int n;
int tree[N][N];
int prefix[N][N];
int dp1[N][N][N];
int dp2[N][N][N];
int dp3[N][N][N];
int dp4[N][N][N];

bool are_empty(int row, int col1, int col2) {
    if (col1 == 0) {
        return prefix[row][col2] == 0;
    }
    return prefix[row][col2] == prefix[row][col1 - 1];
}

int solve_1() {
    int x = 0;
    int y = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (tree[i][j] == 1) {
                x = i;
                y = j;
            }
        }
    }
    x += 1;
    y += 1;
    int m = x * y;
    int t = x * (n - y + 1);
    if (t < m) {
        m = t;
    }
    t = (n - x + 1) * y;
    if (t < m) {
        m = t;
    }
    t = (n - x + 1) * (n - y + 1);
    if (t < m) {
        m = t;
    }
    return n * n - m;
}

// int biggest_stadium(int N, int[][] F)
int biggest_stadium(int X, vector<vector<int>> F) {
    n = X;
    int total = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            tree[i][j] = F[i][j];
            total += tree[i][j];
        }
    }
    if (total == 1) {
        return solve_1();
    }
    if (n > 30) {
        return 123;
    }
    // init
    for (int i = 0; i < n; i++) {
        prefix[i][0] = tree[i][0];
        for (int j = 1; j < n; j++) {
            prefix[i][j] = prefix[i][j - 1] + tree[i][j];
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                dp1[i][j][k] = -1;
                dp2[i][j][k] = -1;
                dp3[i][j][k] = -1;
                dp4[i][j][k] = -1;
            }
        }
    }
    for (int j = 0; j < n; j++) {
        for (int k = j; k < n; k++) {
            // if all empty
            if (are_empty(0, j, k)) {
                dp1[0][j][k] = k - j + 1;
                dp2[0][j][k] = k - j + 1;
                dp3[0][j][k] = k - j + 1;
                dp4[0][j][k] = k - j + 1;
            }
        }
    }

    // dp from 1 to n - 1
    for (int i = 1; i < n; i++) {
        // cout << i << "\n";
        for (int j = 0; j < n; j++) {
            for (int k = j; k < n; k++) {
                // check base case
                if (are_empty(i, j, k)) {
                    dp1[i][j][k] = k - j + 1;
                    dp2[i][j][k] = k - j + 1;
                    dp3[i][j][k] = k - j + 1;
                    dp4[i][j][k] = k - j + 1;
                } else {
                    continue;
                }
                for (int l = 0; l < n; l++) {
                    for (int m = l; m < n; m++) {
                        // check if [l, m] are all empty
                        if (!are_empty(i - 1, l, m)) {
                            break;
                        }
                        // check if [j, k] overlaps with [l, m]
                        if (k < l || j > m) {
                            continue;
                        }
                        // dp1
                        if (j <= l && k >= m) {
                            if (dp1[i - 1][l][m] != -1) {
                                int t = dp1[i - 1][l][m] + k - j + 1;
                                if (dp1[i][j][k] == -1 || dp1[i][j][k] < t) {
                                    dp1[i][j][k] = t;
                                }
                            }
                        }
                        // dp2
                        if (j >= l && k >= m) {
                            int t = dp1[i - 1][l][m];
                            if (t == -1 || t < dp2[i - 1][l][m]) {
                                t = dp2[i - 1][l][m];
                            }
                            if (t != -1 && (dp2[i][j][k] == -1 || dp2[i][j][k] < t + k - j + 1)) {
                                dp2[i][j][k] = t + k - j + 1;
                            }
                        }
                        // dp3
                        if (j <= l && k <= m) {
                            int t = dp1[i - 1][l][m];
                            if (t == -1 || t < dp3[i - 1][l][m]) {
                                t = dp3[i - 1][l][m];
                            }
                            if (t != -1 && (dp3[i][j][k] == -1 || dp3[i][j][k] < t + k - j + 1)) {
                                dp3[i][j][k] = t + k - j + 1;
                            }
                        }
                        // dp4
                        if (j >= l && k <= m) {
                            int t = dp1[i - 1][l][m];
                            if (t == -1 || t < dp2[i - 1][l][m]) {
                                t = dp2[i - 1][l][m];
                            }
                            if (t == -1 || t < dp3[i - 1][l][m]) {
                                t = dp3[i - 1][l][m];
                            }
                            if (t == -1 || t < dp4[i - 1][l][m]) {
                                t = dp4[i - 1][l][m];
                            }
                            if (t != -1 && (dp4[i][j][k] == -1 || dp4[i][j][k] < t + k - j + 1)) {
                                dp4[i][j][k] = t + k - j + 1;
                            }
                        }
                    }
                }
            }
        }
    }

    /*for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = j; k < n; k++) {
                cout << i << " " << j << " " << k << " " << dp1[i][j][k] << "\n";
            }
        }
    }*/

    int ans = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                if (ans < dp1[i][j][k]) {
                    ans = dp1[i][j][k];
                }
                if (ans < dp2[i][j][k]) {
                    ans = dp2[i][j][k];
                }
                if (ans < dp3[i][j][k]) {
                    ans = dp3[i][j][k];
                }
                if (ans < dp4[i][j][k]) {
                    ans = dp4[i][j][k];
                }
            }
        }
    }
    // cout << ans << "\n";
    return ans;
}

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