Submission #348427

#	Time	Username	Problem	Language	Result	Execution time	Memory
348427		casperwang	Red-blue table (IZhO19_stones)	C++14	100 / 100	78 ms	3436 KiB

stones

#include <bits/stdc++.h>
#define pii pair<int,int>
#define All(x) x.begin(), x.end()
using namespace std;
#define debug(args...) kout("[ " + string(#args) + " ]", args)
void kout() { cerr << endl; }
template <class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ',kout(b...); }
template <class T> void pary(T L, T R) { while (L != R) cerr << *L << " \n"[++L==R]; }

int t, n, m;
vector<vector<char>> A, B;
vector <pii> cnt;
int ansA, ansB;

void init() {
  A.clear(), B.clear();
  A.resize(n), B.resize(n);
  for (int i = 0; i < n; i++)
    A[i].resize(m), B[i].resize(m);
  ansA = n, ansB = m;
}

void check() {
  int tmp = ansA;
  for (int i = 0; i < n; i++) {
    int c = 0;
    for (int j = 0; j < m; j++) {
      if (A[i][j] == '+') c++;
    }
    if (c * 2 > m) tmp--;
  }
  for (int i = 0; i < m; i++) {
    int c = 0;
    for (int j = 0; j < n; j++) {
      if (A[j][i] == '-') c++;
    }
    if (c * 2 > n) tmp--;
  }
  assert(!tmp);
  tmp = ansB;
  for (int i = 0; i < n; i++) {
    int c = 0;
    for (int j = 0; j < m; j++) {
      if (B[i][j] == '+') c++;
    }
    if (c * 2 > m) tmp--;
  }
  for (int i = 0; i < m; i++) {
    int c = 0;
    for (int j = 0; j < n; j++) {
      if (B[j][i] == '-') c++;
    }
    if (c * 2 > n) tmp--;
  }
  assert(!tmp);
}

signed main() {
  ios_base::sync_with_stdio(0), cin.tie(0);
  cin >> t;
  while (t--) {
    cin >> n >> m;
    init();
    cnt.clear(), cnt.resize(n);
    for (int i = 0; i < n; i++)
      cnt[i] = pii(0, i);
    for (int i = 0; i < m; i++) {
      int c = (n+2)/2;
      sort(All(cnt));
      for (auto &[v, j] : cnt) {
        if (c > 0 && v < (m-1)/2) {
          A[j][i] = '-';
          v++, c--;
        } else {
          A[j][i] = '+';
        }
      }
      if (!c) ansA++;
    }
    cnt.clear(), cnt.resize(m);
    for (int i = 0; i < m; i++)
      cnt[i] = pii(0, i);
    for (int i = 0; i < n; i++) {
      int c = (m+2)/2;
      sort(All(cnt));
      for (auto &[v, j] : cnt) {
        if (c > 0 && v < (n-1)/2) {
          B[i][j] = '+';
          v++, c--;
        } else {
          B[i][j] = '-';
        }
      }
      if (!c) ansB++;
    }
    check();
    if (ansA > ansB) {
      cout << ansA << '\n';
      for (auto v : A) {
        for (char c : v) {
          cout << c;
        }
        cout << '\n';
      }
    } else {
      cout << ansB << '\n';
      for (auto v : B) {
        for (char c : v) {
          cout << c;
        }
        cout << '\n';
      }
    }
  }
}

Compilation message (stderr)

stones.cpp: In function 'int main()':
stones.cpp:70:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   70 |       for (auto &[v, j] : cnt) {
      |                  ^
stones.cpp:86:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   86 |       for (auto &[v, j] : cnt) {
      |                  ^

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