Submission #842671

#	Time	Username	Problem	Language	Result	Execution time	Memory
842671		nonono	Soccer Stadium (IOI23_soccer)	C++17	48 / 100	4610 ms	1726944 KiB

soccer

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

const int mxN = 505;

void upMax(int &x, int y) {
    x = max(x, y);
}

int sub1(int N, vector<vector<int>> F) {
    for(int i = 0; i < N; i ++) {
        for(int j = 0; j < N; j ++) {
            if(F[i][j] == 1) {
                return max({
                    N * i + N * j - i * j,
                    N * i + N * (N - j - 1) - i * (N - j - 1),
                    N * (N - i - 1) + N * j - (N - i - 1) * j,
                    N * (N - i - 1) + N * (N - j - 1) - (N - i - 1) * (N - j - 1)
                });
            }
        }
    }

    return N * N;
}

map<int, int> low[mxN][mxN];

int sub5(int N, vector<vector<int>> F) {
    vector<vector<int>> sum(N, vector<int> (N, 0)), high(N, vector<int> (N, 0));

    for(int i = 0; i < N; i ++) {
        for(int j = 0; j < N; j ++) {
            sum[i][j] = (j ? sum[i][j - 1] : 0) + F[i][j];
        }
    }

    auto get_sum = [&] (int row, int l, int r) {
        return sum[row][r] - (!l ? 0 : sum[row][l - 1]);
    };

    for(int i = 0; i < N; i ++) {
        for(int j = 0; j < N; j ++) {
            high[i][j] = (F[i][j] ? 0 : (i ? high[i - 1][j] : 0) + 1);
        }
    }

    for(int i = 0; i < N; i ++) {
        for(int k = 0; k < N; k ++) {
            int x = high[i][k];

            for(int j = k; j >= 0; j --) {
                x = min(x, high[i][j]);
                low[i][j][k] = x;
            }
        }
    }

    vector<vector<int>> dp(N, vector<int> (N, 0));
    int result = 0;

    for(int row = 0; row < N; row ++) {
        for(int i = 0; i < N; i ++) {
            for(int j = i; j < N; j ++) {
                if(get_sum(row, i, j)) dp[i][j] = 0;
            }
        }

        for(int i = 0, j = 0; i < N; i = j + 1) {
            for(j = i; j + 1 < N && F[row][j + 1] == F[row][i]; ) j ++ ;
            if(F[row][i]) continue ;

            for(int k = (j - i + 1); k > 0; k --) {
                for(int l = i; l + k - 1 <= j; l ++) {
                    int r = l + k - 1;

                    if(k > 1) {
                        if(l + 1 < N) upMax(dp[l + 1][r], dp[l][r] + low[row][l][r]);
                        if(r - 1 >= 0) upMax(dp[l][r - 1], dp[l][r] + low[row][l][r]);
                    } else {
                        upMax(result, dp[l][r] + low[row][l][r]);
                    }
                }
            }
        }
    }

    return result;
}

int biggest_stadium(int N, vector<vector<int>> F) {
    if(N <= 500) return sub5(N, F);
    return sub1(N, F);
}

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