Submission #1076909

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076909		mickey080929	Soccer Stadium (IOI23_soccer)	C++17	77.50 / 100	655 ms	512892 KiB

soccer

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

using namespace std;

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};

int dp[510][510][510];
vector<pair<int,int>> ran[510][510];

int large_case(int N, vector<vector<int>> F) {
    vector<vector<int>> vis(N, vector<int>(N, 0));
    queue<pair<int,int>> q;
    for (int i=0; i<N; i++) {
        for (int j=0; j<N; j++) {
            if (F[i][j] == 0) {
                vis[i][j] = 1;
                q.push({i, j});
                break;
            }
        }
        if (!q.empty()) break;
    }
    while (!q.empty()) {
        int x = q.front().first;
        int y = q.front().second;
        q.pop();
        for (int k=0; k<4; k++) {
            int nx = x + dx[k];
            int ny = y + dy[k];
            if (nx < 0 || nx >= N || ny < 0 || ny >= N) continue;
            if (vis[nx][ny]) continue;
            if (F[nx][ny]) continue;
            vis[nx][ny] = 1;
            q.push({nx, ny});
        }
    }
    for (int i=0; i<N; i++) {
        for (int j=0; j<N; j++) {
            if (F[i][j] == 0 && vis[i][j] == 0) {
                return 0;
            }
        }
    }
    int tot = 0;
    bool flag = false;
    int pl = -1, pr = -1;
    vector<pair<int,int>> ran;
    for (int i=0; i<N; i++) {
        int l = -1, r = -1, cnt = 0;
        for (int j=0; j<N; j++) {
            if (F[i][j] == 0) {
                if (l == -1) l = j;
                r = j;
                cnt ++;
            }
        }
        if (cnt == 0) {
            pl = -1; pr = -1;
            continue;
        }
        ran.push_back({l, r});
        if (r - l + 1 != cnt) {
            return 0;
        }
        if (pl != -1) {
            if (!flag) {
                if (l <= pl && pr <= r) {}
                else if (pl <= l && r <= pr) {
                    flag = true;
                }
                else return 0;
            }
            else {
                if (pl <= l && r <= pr) {}
                else return 0;
            }
        }
        pl = l; pr = r;
        tot += cnt;
    }
    sort(ran.begin(), ran.end(), [&](pair<int,int> &u, pair<int,int> &v) {
        return u.second - u.first < v.second - v.first;
    });
    for (int i=0; i+1<ran.size(); i++) {
        if (ran[i+1].first <= ran[i].first && ran[i].second <= ran[i+1].second) {}
        else return 0;
    }
    return tot;
}

int biggest_stadium(int N, vector<vector<int>> F) {
    int tot = 0;
    for (int i=0; i<N; i++) {
        for (int j=0; j<N; j++) {
            if (F[i][j] == 1) {
                tot ++;
            }
        }
    }
    if (tot == 0) return N * N;
    if (tot == 1) {
        for (int i=0; i<N; i++) {
            for (int j=0; j<N; j++) {
                if (F[i][j] == 1) {
                    return N * N - min(i+1, N-i) * min(j+1, N-j);
                }
            }
        }
    }
    if (N > 500) {
        return large_case(N, F);
    }
    for (int i=0; i<N; i++) {
        vector<int> cnt(N, 0);
        for (int j=i; j<N; j++) {
            for (int k=0; k<N; k++) {
                if (F[j][k] == 0) {
                    cnt[k] ++;
                }
            }
            int l = -1;
            for (int k=0; k<N; k++) {
                if (cnt[k] == j-i+1) {
                    if (l == -1) l = k;
                    if (k == N-1 || cnt[k+1] != j-i+1) {
                        ran[i][j].push_back({l, k});
                    }
                }
                else l = -1;
            }
        }
    }
    int ans = 0;
    for (int i=0; i<N; i++) {
        for (int j=0; j<ran[i][i].size(); j++) {
            dp[i][i][j] = ran[i][i][j].second - ran[i][i][j].first + 1;
            ans = max(ans, dp[i][i][j]);
        }
    }
    for (int d=1; d<=N-1; d++) {
        for (int i=0; i<N-d; i++) {
            int j = i + d;
            int l = 0;
            for (int k=0; k<ran[i][j].size(); k++) {
                while (ran[i][j-1][l].second < ran[i][j][k].first)
                    l ++;
                dp[i][j][k] = max(dp[i][j][k], dp[i][j-1][l] + ran[i][j][k].second - ran[i][j][k].first + 1);
                ans = max(ans, dp[i][j][k]);
            }
            l = 0;
            for (int k=0; k<ran[i][j].size(); k++) {
                while (ran[i+1][j][l].second < ran[i][j][k].first)
                    l ++;
                dp[i][j][k] = max(dp[i][j][k], dp[i+1][j][l] + ran[i][j][k].second - ran[i][j][k].first + 1);
                ans = max(ans, dp[i][j][k]);
            }
        }
    }
    return ans;
}

Compilation message (stderr)

soccer.cpp: In function 'int large_case(int, std::vector<std::vector<int> >)':
soccer.cpp:86:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |     for (int i=0; i+1<ran.size(); i++) {
      |                   ~~~^~~~~~~~~~~
soccer.cpp: In function 'int biggest_stadium(int, std::vector<std::vector<int> >)':
soccer.cpp:137:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  137 |         for (int j=0; j<ran[i][i].size(); j++) {
      |                       ~^~~~~~~~~~~~~~~~~
soccer.cpp:146:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  146 |             for (int k=0; k<ran[i][j].size(); k++) {
      |                           ~^~~~~~~~~~~~~~~~~
soccer.cpp:153:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  153 |             for (int k=0; k<ran[i][j].size(); k++) {
      |                           ~^~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 8 / 8
• Subtask 3: 22 / 22
• Subtask 4: 18 / 18
• Subtask 5: 16 / 16
• Subtask 6: 7.5 / 30