Submission #840724

#	Time	Username	Problem	Language	Result	Execution time	Memory
840724		danikoynov	Soccer Stadium (IOI23_soccer)	C++17	54 / 100	4530 ms	509860 KiB

soccer

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

using namespace std;

const int maxn = 2010;
int a[maxn][maxn], bef[maxn][maxn], aft[maxn][maxn];
int dp[510][510][510], pref[maxn][maxn];

int biggest_stadium(int N, std::vector<std::vector<int>> F)
{
    int cnt = 0;
    int x1 = 0, y1 = 0;
    for (int i = 0; i < N; i ++)
        for (int j = 0; j < N; j ++)
    {
        cnt += F[i][j];
        if (F[i][j] == 1)
            x1 = i + 1, y1 = j + 1;
        a[i + 1][j + 1] = F[i][j];
    }

    if (cnt == 1)
    {
        int ans = N * N - min(x1, N - x1 + 1) * min(y1, N - y1 + 1);
        return ans;
    }

    for (int j = 1; j <= N; j ++)
    {
        for (int i = 1; i <= N; i ++)
            pref[i][j] = pref[i - 1][j] + a[i][j];
    }
    for (int i = 1; i <= N; i ++)
    {
        for (int j = 1; j <= N; j ++)
        {
            if (a[i][j] == 1)
                bef[i][j] = j;
            else
                bef[i][j] = bef[i][j - 1];
        }

        aft[i][N + 1] = N + 1;
        for (int j = N; j > 0; j --)
        {
            if (a[i][j] == 1)
                aft[i][j] = j;
            else
                aft[i][j] = aft[i][j + 1];
        }
    }

    int ans = 0;
    for (int col = 1; col <= N; col ++)
            ///int col = 5;
    {


        for (int len = 1; len <= N; len ++)
        {
            for (int i = 1; i <= N - len + 1; i ++)
            {
                int j = i + len - 1;


                if (pref[j][col] - pref[i - 1][col] > 0)
                    continue;

                if (col != 1 && pref[j][col - 1] - pref[i - 1][col - 1] == 0)
                {
                    dp[col][i][j] = dp[col - 1][i][j];
                    continue;
                }

                int left_width = N, right_width = N;
                for (int k = i; k <= j; k ++)
                {
                    left_width = min(left_width, col - bef[k][col]);
                    right_width = min(right_width, aft[k][col] - col);
                }

                    int base_area = (j - i + 1) * (left_width + right_width - 1);
                dp[col][i][j] = base_area;

                if (left_width != col)
                {
                    vector < int > split;
                    split.push_back(i - 1);
                    for (int k = i; k <= j; k ++)
                    {
                        if (bef[k][col] == col - left_width)
                            split.push_back(k);
                    }
                    split.push_back(j + 1);

                    for (int d = 1; d < (int)(split.size()); d ++)
                    {
                        ///cout << "check " << split[d - 1] + 1 << " " << split[d] - 1 << endl;
                        int rem_area = (split[d] - split[d - 1] - 1) * (left_width + right_width - 1);
                        dp[col][i][j] = max(dp[col][i][j], dp[col][split[d - 1] + 1][split[d] - 1] - rem_area + base_area);
                    }
                }

                if (right_width != N + 1 - col)
                {
                    vector < int > split;
                                        split.push_back(i - 1);
                    for (int k = i; k <= j; k ++)
                    {
                        if (aft[k][col] == col + right_width)
                            split.push_back(k);
                    }
                    split.push_back(j + 1);

                    for (int d = 1; d < (int)(split.size()); d ++)
                    {
                        int rem_area = (split[d] - split[d - 1] - 1) * (left_width + right_width - 1);
                        dp[col][i][j] = max(dp[col][i][j], dp[col][split[d - 1] + 1][split[d] - 1] - rem_area + base_area);
                    }
                }
                ans = max(ans, dp[col][i][j]);
                ///cout << i << " : " << j << " = " << dp[col][i][j] << endl;
            }

        }
    }
    return ans;
}

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