Submission #840694

#	Time	Username	Problem	Language	Result	Execution time	Memory
840694		PurpleCrayon	Soccer Stadium (IOI23_soccer)	C++17	64 / 100	4566 ms	601992 KiB

soccer

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

#define ar array
#define sz(v) int(v.size())
const int M = 2e3+10, INF = 1e9+10;

struct Sparse {
    vector<vector<int>> sparse;
    Sparse() {}
    Sparse(vector<int>& v) {
        int n = v.size();
        sparse.push_back(v);
        for (int i = 1; (1 << i) <= n; i++) {
            sparse.push_back(vector<int>(n - (1 << i) + 1));
            for (int j = 0; j + (1 << i) <= n; j++) {
                sparse[i][j] = min(sparse[i-1][j], sparse[i-1][j + (1 << (i-1))]);
            }
        }
    }

    int qry(int l, int r) {
        assert(l <= r);
        int b = 31 - __builtin_clz(r - l + 1);
        // cerr << "> " << l << ' ' << r << ''
        return min(sparse[b][l], sparse[b][r - (1 << b) + 1]);
    }
} ones[M], twos[M];

int get_cost(int i, int l, int r) {
    return max(0, ones[i].qry(l, r) + twos[i].qry(l, r) - 1);
}

vector<int> impl[M][M];
vector<int> impr[M][M];
vector<int> has[M][M];
unordered_map<int, int> dp[M][M];

int biggest_stadium(int N, std::vector<std::vector<int>> F) {
     for (int i = 0; i < N; i++) {
        vector<int> up(N), down(N);
        for (int j = 0; j < N; j++) {
            while (i - up[j] >= 0 && !F[i - up[j]][j]) up[j]++;
            while (i + down[j] < N && !F[i + down[j]][j]) down[j]++;
            // if (i == 0) cerr << up[j] << ' ' << down[j] << endl;
            // if (i == 0) cerr << "> " << F[i][i + 1]
        }

        ones[i] = Sparse(up), twos[i] = Sparse(down);
    }

    auto add_imp = [&](int i, int l, int r) {
        has[l][r].push_back(i);
        impl[i][l].push_back(r);
        impr[i][r].push_back(l);
    };

    for (int i = 0; i < N; i++) {
        vector<int> blocks{-1};
        for (int j = 0; j < N; j++) if (F[i][j])
            blocks.push_back(j);
        
        blocks.push_back(N);

        for (int j = 1; j < sz(blocks); j++) if (blocks[j] > blocks[j-1] + 1) {
            int l = blocks[j-1]+1, r = blocks[j]-1;
            for (int k = l; k <= r; k++) {
                add_imp(i, k, r);
                if (k != r) add_imp(i, l, k);
            }
        }
    }

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            sort(impl[i][j].begin(), impl[i][j].end());
            sort(impr[i][j].begin(), impr[i][j].end());
        }
    }

    auto upd = [&](int ni, int l, int r, int x, int cur_cost) {
        if (ni < 0 || ni >= N) return;
        int nl = upper_bound(impr[ni][r].begin(), impr[ni][r].end(), l) - impr[ni][r].begin();
        if (nl < sz(impr[ni][r])) {
            nl = impr[ni][r][nl];
            dp[ni][nl][r] = max(dp[ni][nl][r], x + (get_cost(ni, nl, r) - cur_cost) * (r - nl + 1));
        }

        int nr = lower_bound(impl[ni][l].begin(), impl[ni][l].end(), r) - impl[ni][l].begin() - 1;
        if (nr >= 0) {
            nr = impl[ni][l][nr];
            dp[ni][l][nr] = max(dp[ni][l][nr], x + (get_cost(ni, l, nr) - cur_cost) * (nr - l + 1));
        }
    };

    for (int l = 0; l < N; l++) {
        for (int r = N-1; r >= 0; r--) {
            for (int i : has[l][r]) {
                int cur_cost = get_cost(i, l, r);
                int store = dp[i][l][r] = max(dp[i][l][r], cur_cost * (r - l + 1));
                // cerr << l << ' ' << r << ' ' << i << ' ' << dp[{i, l, r}] << endl;

                int top = i - ones[i].qry(l, r);
                int bot = i + twos[i].qry(l, r);
                upd(i, l, r, store, cur_cost);
                upd(top, l, r, store, cur_cost);
                upd(bot, l, r, store, cur_cost);
            }
        }
    }

    int ans = 0;
    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++)
        for (auto& [_, v] : dp[i][j]) ans = max(ans, v);

    cerr << (double)clock() / CLOCKS_PER_SEC << endl;
    return ans;
}

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