Submission #293775

#	Time	Username	Problem	Language	Result	Execution time	Memory
293775		BThero	Furniture (JOI20_furniture)	C++17	100 / 100	3991 ms	7628 KiB

furniture

// chrono::system_clock::now().time_since_epoch().count()
#include<bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define debug(x) cerr << #x << " = " << x << endl;

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int MAXN = (int)1e3 + 5;
const int MAXM = (int)1e6 + 9;

int dp[MAXN][MAXN];
char s[MAXN][MAXN];
int n, m, q;
vector<array<int, 3>> todo;

bool go(int diag, int l, int r) {
  if (l > r) {
    return 0;
  }

  if (diag == 0) {
    return 1;
  }
  
  todo.pb({diag, l, r});
  
  int nl = l, nr = r - 1;
  int x = l - 1, y = diag - l;
  
  if (x >= 0 && dp[x][y + 1] == 0) {
    nl--;
  }
  
  x = r, y = diag - r - 1;
  
  if (y >= 0 && dp[x + 1][y] == 0) {
    nr++;
  }
  
  return go(diag - 1, nl, nr);
}

void solve() {
  scanf("%d %d", &n, &m);
  
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      scanf(" %c", &s[i][j]);
    }
  }
  
  scanf("%d", &q);
  
  for (int x = n - 1; ~x; --x) {
    for (int y = m - 1; ~y; --y) {
      if (x == n - 1 && y == m - 1) {
        dp[x][y] = 1;
        continue;
      }
      
      dp[x][y] = 0;
    
      if (s[x][y] != '1') {
        dp[x][y] |= dp[x + 1][y];
        dp[x][y] |= dp[x][y + 1];
      }
    }
  }
  
  for (int i = 1; i <= q; ++i) {
    int x, y;
    scanf("%d %d", &x, &y);
    --x;
    --y;
    
    if (dp[x][y] == 0) {
      s[x][y] = '1';
      printf("1\n");
      continue;
    }
    
    todo.clear();
    
    if (go(x + y, x, x)) {
      printf("0\n");
    }
    else {
      printf("1\n");
      s[x][y] = '1';
      
      for (auto &[diag, l, r] : todo) {
        for (int i = l; i <= r; ++i) {
          dp[i][diag - i] = 0;
        }
      }
    }
  }
}

int main() {
  int tt = 1;
  
  while (tt--) {
    solve();
  }

  return 0;
}

Compilation message (stderr)

furniture.cpp: In function 'void solve()':
furniture.cpp:53:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   53 |   scanf("%d %d", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~~
furniture.cpp:57:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   57 |       scanf(" %c", &s[i][j]);
      |       ~~~~~^~~~~~~~~~~~~~~~~
furniture.cpp:61:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   61 |   scanf("%d", &q);
      |   ~~~~~^~~~~~~~~~
furniture.cpp:81:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   81 |     scanf("%d %d", &x, &y);
      |     ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95