Submission #293348

#	Time	Username	Problem	Language	Result	Execution time	Memory
293348		Mamnoon_Siam	Furniture (JOI20_furniture)	C++17	0 / 100	3 ms	1536 KiB

furniture

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

using ll = long long;
using ii = pair<int, int>;
using vi = vector<int>;
using vb = vector<bool>;
#define all(v) begin(v), end(v)
const int N = 1e3 + 5;
using bs = bitset<N>;

struct grid {
  int n, m;
  int tp;
  bs blocked[N], vis[N], on_path[N];
  grid() {}
  grid(int _n, int _m, int _tp, bs _blocked[N]) : n(_n), m(_m), tp(_tp) {
    for(int i = 1; i <= n; ++i) {
      blocked[i] = _blocked[i];
    }
    if(tp) {
      swap(n, m);
      for(int i = 1; i <= n; ++i) {
        for(int j = 1; j <= m; ++j) {
          int x = blocked[i][j], y = blocked[j][i];
          blocked[j][i] = x, blocked[i][j] = y;
        }
      }
    }
    find_least_path(1, 1);
  }
  bool find_least_path(int x, int y) {
    if(x > n or y > m) return 0;
    if(blocked[x][y]) return vis[x][y] = 1, 0;
    if(x == n and y == m) {
      on_path[x][y] = 1;
      return 1;
    }
    if(!vis[x][y+1] and find_least_path(x, y+1)) {
      on_path[x][y] = 1;
      return 1;
    }
    if(!vis[x+1][y] and find_least_path(x+1, y)) {
      on_path[x][y] = 1;
      return 1;
    }
    vis[x][y] = 1;
    return 0;
  }
  void destroy(int x, int y) {
    if(tp) swap(x, y);
    blocked[x][y] = 1;
    if(!on_path[x][y]) return;
    for(int i = 1; i <= n; ++i) {
      vis[i].reset(), on_path[i].reset();
    }
    find_least_path(1, 1);
  }
  int fn(int x, int y) {
    if(tp) swap(x, y);
    return on_path[x][y];
  }
};

int main(int argc, char const *argv[])
{
#ifdef LOCAL
  freopen("in", "r", stdin);
#endif
  int n, m;
  scanf("%d %d", &n, &m);
  grid g[2];
  bs blocked[N];
  for(int i = 1; i <= n; ++i) {
    for(int j = 1; j <= m; ++j) {
      int x;
      scanf("%d", &x);
      blocked[i][j] = x;
    }
  }
  for(int i : {0, 1}) {
    g[i] = grid(n, m, i, blocked);
  }
  int q; scanf("%d", &q);
  while(q--) {
    int x, y;
    scanf("%d %d", &x, &y);
    if(g[0].fn(x, y) and g[1].fn(x, y)) {
      puts("0");
    } else {
      puts("1");
      for(int i : {0, 1}) {
        g[i].destroy(x, y);
      }
    }
  }
  return 0;
}

Compilation message (stderr)

furniture.cpp: In function 'int main(int, const char**)':
furniture.cpp:71:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   71 |   scanf("%d %d", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~~
furniture.cpp:77:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   77 |       scanf("%d", &x);
      |       ~~~~~^~~~~~~~~~
furniture.cpp:84:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   84 |   int q; scanf("%d", &q);
      |          ~~~~~^~~~~~~~~~
furniture.cpp:87:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   87 |     scanf("%d %d", &x, &y);
      |     ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95