Submission #898287

#	Time	Username	Problem	Language	Result	Execution time	Memory
898287		vjudge1	Red-blue table (IZhO19_stones)	C++17	54 / 100	1272 ms	3372 KiB

stones

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

const int N = 1e3;

int t, n, m, ans, r[N], c[N];
char a[2][N][N];
string b[3];

int f() {
  for (int i = 0; i < n; i++) {
    r[i] = 0;
  }
  for (int i = 0; i < m; i++) {
    c[i] = 0;
  }

  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (a[1][i][j] == '+') r[i]++;
      else c[j]++;
    }
  }

  int y = 0;
  for (int i = 0; i < n; i++) {
    y += (r[i] > m/2);
  }
  for (int i = 0; i < m; i++) {
    y += (c[i] > n/2);
  }
  return y;
}

signed main() {
  ios::sync_with_stdio(false); cin.tie(nullptr);

  cin >> t;
  while (t--) {
    cin >> n >> m;
    ans = 0;
      
      b[0].clear();
      b[0].resize(n, '+');
      for (int i = 0; i <= n/2; i++) {
        b[0][i] = '-';
      }

      b[1].clear();
      b[1].resize(n, '+');
      for (int i = 0; i <= n/2; i++) {
        b[1][n-1-i] = '-';
      }

      b[2].clear();
      b[2].resize(n, '+');
      for (int i = 0; i <= n/4; i++) {
        b[2][i] = '-';
        b[2][n-1-i] = '-';
      }
      
      int x = (m-1) / 2 / 2 * 3 + ((m-1)/2 % 2 ? 1 : 0);
      for (int i = 0; i <= n; i++) {
        for (int j = 0; j < m-x; j++) {
          a[1][i][j] = '+';
        }

        int curr = 0;
        for (int j = m-x; j < m; j++) {
          a[1][i][j] = b[curr][i];
          curr = (curr+1) % 3;
        }
      }

      x = f();
      if (x > ans) {
        ans = x;
        swap(a[0], a[1]);
      }
      
      b[0].clear();
      b[0].resize(m, '-');
      for (int i = 0; i <= m/2; i++) {
        b[0][i] = '+';
      }

      b[1].clear();
      b[1].resize(m, '-');
      for (int i = 0; i <= m/2; i++) {
        b[1][m-1-i] = '+';
      }

      b[2].clear();
      b[2].resize(m, '-');
      for (int i = 0; i <= m/4; i++) {
        b[2][i] = '+';
        b[2][m-1-i] = '+';
      }
      
      x = (n-1) / 2 / 2 * 3 + ((n-1)/2 % 2 ? 1 : 0);
      for (int j = 0; j <= m; j++) {
        for (int i = 0; i < n-x; i++) {
          a[1][i][j] = '-';
        }

        int curr = 0;
        for (int i = n-x; i < n; i++) {
          a[1][i][j] = b[curr][j];
          curr = (curr+1) % 3;
        }
      }

      x = f();
      if (x > ans) {
        ans = x;
        swap(a[0], a[1]);
      }

    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        a[1][i][j] = '+';
      }
    }
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        if ((i <= n/2 && j < m/2) || (i >= n/2 && j > m/2)) a[1][i][j] = '-';
      }
    }
    x = f();
    if (x > ans) {
      ans = x;
      swap(a[0], a[1]);
    }

    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        a[1][i][j] = '+';
      }
    }
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        if ((i < n/2 && j <= m/2) || (i > n/2 && j >= m/2)) a[1][i][j] = '+';
      }
    }
    x = f();
    if (x > ans) {
      ans = x;
      swap(a[0], a[1]);
    }

    cout << ans << "\n";
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        cout << a[0][i][j];
      }
      cout << "\n";
    }

/*
    if (n%2 == 0 && m%2 == 0) {

    }
    else if (n%2 == 0 && m%2 == 1) {

    }
    else if (n%2 == 1 && m%2 == 0) {

    }
    else if (n%2 == 1 && m%2 == 1) {

    }
    */
  }
}


/*
--++++
++--++
++++--
------
------

--++++
----++
------
++----
++++--
*/

• Subtask 1: 17 / 17
• Subtask 2: 10 / 10
• Subtask 3: 16 / 16
• Subtask 4: 11 / 11
• Subtask 5: 0 / 15
• Subtask 6: 0 / 31