Problem p02579 (C++) — buggy submission, verdict: Time Limit Exceeded


// Problem : D - Wizard in Maze
// Contest : AtCoder - AtCoder Beginner Contest 176
// URL : https://atcoder.jp/contests/abc176/tasks/abc176_d
// Memory Limit : 1024 MB
// Time Limit : 2000 ms
// Powered by CP Editor (https://github.com/cpeditor/cpeditor)

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;

/* DEBUGGING */
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define deb(x...)                                                              \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define deb(x...)
#endif

/* MACROS */
typedef long long int ll;

typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<pii, int> ppi;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;

typedef map<int, int> mii;

#define ff first
#define ss second
#define pb push_back
#define IOS                                                                    \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);                                                               \\
  cout.tie(NULL);
#define lb lower_bound
#define ub upper_bound
#define all(x) (x).begin(), (x).end()
#define ps(x, y) fixed << setprecision(y) << x
#define setbit(x) __builtin_popcountll(x)
#define rep(i, a, b) for (int i = a; i < b; ++i)
#define repr(i, a, b) for (int i = a; i >= b; --i)

/* CONSTANTS */
#define PI 3.141592653589793
const ll MOD = 1e9 + 7;
const ll INF = 1000000000;
const ll MAX_N = 1e3 + 5;

// #define cerr if(false)cerr
/* CODE STARTS HERE */

int r, c;
int grid[MAX_N][MAX_N], vis[MAX_N][MAX_N], dist[MAX_N][MAX_N];

bool check(int x, int y) {
  if (x <= 0 || y <= 0 || x > r || y > c)
    return false;
  if (grid[x][y])
    return false;

  return true;
}

void solve() {
  cin >> r >> c;
  int st_x, st_y;
  cin >> st_x >> st_y;
  int ed_x, ed_y;
  cin >> ed_x >> ed_y;

  char ch;
  rep(i, 1, r + 1) {
    rep(j, 1, c + 1) {
      cin >> ch;
      grid[i][j] = (ch == '#' ? 1 : 0);
      dist[i][j] = INF;
      vis[i][j] = 0;
    }
  }

  vi dx =
         {
             1,
             -1,
             0,
             0,
         },
     dy = {0, 0, -1, 1};
  deque<pii> dq;
  int nx, ny;

  dq.push_front({st_x, st_y});
  dist[st_x][st_y] = 0;

  while (!dq.empty()) {
    pii node = dq.front();
    dq.pop_front();
    int x = node.ff, y = node.ss;
    // deb(x , y , dist[x][y]);

    if (x == ed_x && y == ed_y) {
      cout << dist[x][y];
      return;
    }

    if (vis[x][y])
      continue;
    vis[x][y] = 1;

    rep(i, 0, 4) {
      nx = x + dx[i], ny = y + dy[i];

      if (check(nx, ny) && vis[nx][ny] == 0) {
        dq.push_front({nx, ny});
        dist[nx][ny] = dist[x][y];
      }
    }

    rep(i, -2, 3) {
      rep(j, -2, 3) {
        nx = x + i, ny = y + j;

        if (check(nx, ny) && vis[nx][ny] == 0 && dist[nx][ny] == INF) {
          dq.push_back({nx, ny});
          dist[nx][ny] = dist[x][y] + 1;
        }
      }
    }
  }

  cout << "-1";
}

int main() {
  IOS;
  solve();
}

Error: TLE

Fixed submission:


// Problem : D - Wizard in Maze
// Contest : AtCoder - AtCoder Beginner Contest 176
// URL : https://atcoder.jp/contests/abc176/tasks/abc176_d
// Memory Limit : 1024 MB
// Time Limit : 2000 ms
// Powered by CP Editor (https://github.com/cpeditor/cpeditor)

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;

/* DEBUGGING */
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define deb(x...)                                                              \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define deb(x...)
#endif

/* MACROS */
typedef long long int ll;

typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<pii, int> ppi;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;

typedef map<int, int> mii;

#define ff first
#define ss second
#define pb push_back
#define IOS                                                                    \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);                                                               \\
  cout.tie(NULL);
#define lb lower_bound
#define ub upper_bound
#define all(x) (x).begin(), (x).end()
#define ps(x, y) fixed << setprecision(y) << x
#define setbit(x) __builtin_popcountll(x)
#define rep(i, a, b) for (int i = a; i < b; ++i)
#define repr(i, a, b) for (int i = a; i >= b; --i)

/* CONSTANTS */
#define PI 3.141592653589793
const ll MOD = 1e9 + 7;
const ll INF = 1000000000;
const ll MAX_N = 2e5 + 2;

// #define cerr if(false)cerr
/* CODE STARTS HERE */

void solve() {
  int r, c;
  cin >> r >> c;
  int sr, sc;
  cin >> sr >> sc;
  int er, ec;
  cin >> er >> ec;

  int vis[r + 1][c + 1], dist[r + 1][c + 1];
  int grid[r + 1][c + 1];
  string s;

  rep(i, 1, r + 1) {
    cin >> s;
    rep(j, 1, c + 1) grid[i][j] = (s[j - 1] == '#'), vis[i][j] = 0,
                     dist[i][j] = 0;
  }

  /*rep(i,1,r+1){
      rep(j,1,c+1) cout << grid[i][j] << " ";
      cout << "\\n";
  }*/

  deque<pii> dq;
  vi dx = {1, -1, 0, 0}, dy = {0, 0, 1, -1};
  vpii v;

  dq.push_front({sr, sc});
  vis[sr][sc] = 1;
  dist[sr][sc] = 0;

  while (!dq.empty()) {
    pii node = dq.front();
    dq.pop_front();
    int x = node.ff, y = node.ss;
    // deb(x , y);
    if (x == er && y == ec) {
      cout << dist[er][ec];
      return;
    }

    // v.clear();
    rep(i, 0, 4) {
      int nx = x + dx[i];
      int ny = y + dy[i];
      if (nx <= 0 || nx > r || ny <= 0 || ny > c)
        continue;
      if (vis[nx][ny] || grid[nx][ny])
        continue;

      vis[nx][ny] = 1;
      dq.push_front({nx, ny});
      dist[nx][ny] = dist[x][y];
      v.pb({nx, ny});
    }
    // deb(v);

    rep(i, -2, 3) {
      rep(j, -2, 3) {
        int nx = x + i;
        int ny = y + j;
        if (nx <= 0 || nx > r || ny <= 0 || ny > c)
          continue;
        if (vis[nx][ny] || grid[nx][ny])
          continue;

        // vis[nx][ny] = 1;
        dq.push_back({nx, ny});
        dist[nx][ny] = dist[x][y] + 1;
        v.pb({nx, ny});
      }
    }
    // deb(v);
  }

  cout << "-1";
}

int main() {
  IOS;
  solve();
}