Submission #156394

#	Time	Username	Problem	Language	Result	Execution time	Memory
156394		ASDF123	Red-blue table (IZhO19_stones)	C++14	100 / 100	33 ms	2336 KiB

stones

#include <bits/stdc++.h>
//#define int long long
#define pii pair<int, int>
#define fr first
#define sc second
#define all(s) s.begin(), s.end()
#define szof(s) (int)s.size()
#define Ok puts("Ok")
using namespace std;

const int N = (int)1e3 + 5;
const int INF = 0x3f3f3f3f;
const int MOD = (int)1e9 + 9;

int tests = 1;
int n, m, ans;
char a[N][N], c[N][N];
vector <pair<int, int>> row, col;

void init() {
  row.clear();
  col.clear();
  ans = 0;
}


inline void solve() {
  init();
  cin >> n >> m;

  if (m >= n) {
    ans = m;
    int can = n - (n / 2 + 1);
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++) {
        c[i][j] = '-';
      }
    }

    for (int j = 1; j <= m; j++) {
      col.push_back({j, can});
    }

    int need = m / 2 + 1;
    for (int i = 1; i <= n; i++) {
      if (col.empty() || col.size() < need) {
        break;
      }
      int cnt = 0;
      sort (all(col), [&](pii A, pii B) {
          return A.sc > B.sc;
        });
      for (int j = 0; j < need; j++) {
        if (col[j].sc) {
          cnt++;
        }
      }
      if (cnt == need) {
        ans++;
        for (int j = 0; j < need; j++) {
          c[i][col[j].fr] = '+';
          col[j].sc--;
        }
      } else {
        break;
      }

      while (!col.empty() && col.back().sc == 0) {
        col.pop_back();
      }
    }
  }
  else {
    ans = n;
    int can = m - (m / 2 + 1);
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++) {
        c[i][j] = '+';
      }
    }

    for (int i = 1; i <= n; i++) {
      row.push_back({i, can});
    }

    int need = n / 2 + 1;
    for (int j = 1; j <= m; j++) {
      if (row.empty() || row.size() < need) {
        break;
      }

      int cnt = 0;
      sort (all(row), [&](pii A, pii B) {
        return A.sc > B.sc;
      });
      for (int i = 0; i < need; i++) {
        if (row[i].sc) {
          cnt++;
        }
      }
      if (cnt == need) {
        ans++;
        for (int i = 0; i < need; i++) {
          c[row[i].fr][j] = '-';
          row[i].sc--;
        }
      } else {
        break;
      }

      while (!row.empty() && row.back().sc == 0) {
        row.pop_back();
      }
    }
  }

  printf("%d\n", ans);
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      putchar(c[i][j]);
    }printf("\n");
  }
}

main() {
  cin >> tests;
  while (tests--) {
    solve();
  }
}

Compilation message (stderr)

stones.cpp: In function 'void solve()':
stones.cpp:46:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       if (col.empty() || col.size() < need) {
                          ~~~~~~~~~~~^~~~~~
stones.cpp:88:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       if (row.empty() || row.size() < need) {
                          ~~~~~~~~~~~^~~~~~
stones.cpp: At global scope:
stones.cpp:125:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^

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