Problem p02579 (C++) — buggy submission, verdict: Runtime Error

// #include <bits/stdc++.h>
// #pragma GCC optimize(2)
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <time.h>
#include <vector>

#define X first
#define Y second
#define PB push_back
#define MP make_pair
#define scd(a) scanf("%d", &a)
#define scdd(a, b) scanf("%d%d", &a, &b)
#define scddd(a, b, c) scanf("%d%d%d", &a, &b, &c)
#define ALL(x) x.begin(), x.end()
#define sz(a) ((int)a.size())
#define getmid ((l + r) >> 1)
#define mst(var, val) memset(var, val, sizeof(var))
#define IOS                                                                    \\
  ios::sync_with_stdio(false);                                                 \\
  cin.tie(0)
#define lowbit(x) x & (-x)
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep1(i, n) for (int i = 1; i <= n; ++i)
#define ls rt << 1
#define rs rt << 1 | 1
using namespace std;
#ifdef local
#define dbg(args...) cout << #args << " -> ", err(args);
void err() { cout << endl; }
template <typename T, typename... Args> void err(T a, Args... args) {
  cout << a << ' ';
  err(args...);
}
#else
#define dbg(args...)
#endif // local

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<double, double> pdd;
const int inf = 0x3f3f3f3f;
const long long INF = 0x3f3f3f3f3f3f3f3fLL;
const double PI = acos(-1.0);
const long double eps = 1e-8;
const int mod = 1e9 + 7;
const int maxn = 3e5 + 100;
const int N = 2e5 + 1000;
const int M = 500 + 10;
const ll mm = (1LL << 32);

template <class T> inline void read(T &x) {
  x = 0;
  char c = getchar();
  bool f = 0;
  for (; !isdigit(c); c = getchar())
    f ^= c == '-';
  for (; isdigit(c); c = getchar())
    x = x * 10 + (c ^ 48);
  x = f ? -x : x;
}

template <class T> inline void write(T x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  T y = 1;
  int len = 1;
  for (; y <= x / 10; y *= 10)
    ++len;
  for (; len; --len, x %= y, y /= 10)
    putchar(x / y + 48);
}
ll qpow(ll a, ll b, ll mod) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      ans = (ans * a) % mod;
    b >>= 1;
    a = (a * a) % mod;
  }
  return ans;
}

struct node {
  int x, y, d;
  bool operator<(const node &b) const { return d > b.d; }
};

int dis[1010][1010];
char s[1010][1010];
int n, m, fs, ft, es, et;
bool is(int x, int y) {
  return x >= 1 && x <= n && y >= 1 && y <= m && s[x][y] == '.';
}
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
int tx[] = {-2, -2, -2, -2, -2, -1, -1, -1, -1, -1, 0, 0,
            0,  0,  1,  1,  1,  1,  1,  2,  2,  2,  2, 2};
int ty[] = {-2, -1, 0,  1,  2, -2, -1, 0,  1,  2, -2, -1,
            1,  2,  -2, -1, 0, 1,  2,  -2, -1, 0, 1,  2};
void dij() {
  priority_queue<node> q;
  dis[fs][ft] = 0;
  q.push({fs, ft, 0});
  while (!q.empty()) {
    node tmp = q.top();
    q.pop();
    int x = tmp.x, y = tmp.y, d = tmp.d;
    if (d > dis[x][y])
      continue;
    int nx, ny;
    for (int i = 0; i < 4; ++i) {
      nx = x + dx[i];
      ny = y + dy[i];
      if (is(nx, ny) && dis[nx][ny] > dis[x][y]) {
        dis[nx][ny] = dis[x][y];
        q.push({nx, ny, dis[nx][ny]});
      }
    }
    for (int i = 0; i < 24; ++i) {
      nx = x + tx[i];
      ny = y + ty[i];
      if (is(nx, ny) && dis[nx][ny] > dis[x][y] + 1) {
        dis[nx][ny] = dis[x][y] + 1;
        q.push({nx, ny, dis[nx][ny]});
      }
    }
  }
}
int main() {
#ifdef local
  freopen("in.txt", "r", stdin);
#endif // local
  IOS;
  cout.tie(0);
  cin >> n >> m;
  cin >> fs >> ft;
  cin >> es >> et;
  rep1(i, n) cin >> (s[i] + 1);
  mst(dis, inf);
  dij();
  if (dis[es][et] == inf)
    cout << -1 << endl;
  else
    cout << dis[es][et] << endl;
  return 0;
}


Error: 0

Fixed submission:

// #include <bits/stdc++.h>
// #pragma GCC optimize(2)
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <time.h>
#include <vector>

#define X first
#define Y second
#define PB push_back
#define MP make_pair
#define scd(a) scanf("%d", &a)
#define scdd(a, b) scanf("%d%d", &a, &b)
#define scddd(a, b, c) scanf("%d%d%d", &a, &b, &c)
#define ALL(x) x.begin(), x.end()
#define sz(a) ((int)a.size())
#define getmid ((l + r) >> 1)
#define mst(var, val) memset(var, val, sizeof(var))
#define IOS                                                                    \\
  ios::sync_with_stdio(false);                                                 \\
  cin.tie(0)
#define lowbit(x) x & (-x)
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep1(i, n) for (int i = 1; i <= n; ++i)
#define ls rt << 1
#define rs rt << 1 | 1
using namespace std;
#ifdef local
#define dbg(args...) cout << #args << " -> ", err(args);
void err() { cout << endl; }
template <typename T, typename... Args> void err(T a, Args... args) {
  cout << a << ' ';
  err(args...);
}
#else
#define dbg(args...)
#endif // local

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<double, double> pdd;
const int inf = 0x3f3f3f3f;
const long long INF = 0x3f3f3f3f3f3f3f3fLL;
const double PI = acos(-1.0);
const long double eps = 1e-8;
const int mod = 1e9 + 7;
const int maxn = 3e5 + 100;
const int N = 2e5 + 1000;
const int M = 500 + 10;
const ll mm = (1LL << 32);

template <class T> inline void read(T &x) {
  x = 0;
  char c = getchar();
  bool f = 0;
  for (; !isdigit(c); c = getchar())
    f ^= c == '-';
  for (; isdigit(c); c = getchar())
    x = x * 10 + (c ^ 48);
  x = f ? -x : x;
}

template <class T> inline void write(T x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  T y = 1;
  int len = 1;
  for (; y <= x / 10; y *= 10)
    ++len;
  for (; len; --len, x %= y, y /= 10)
    putchar(x / y + 48);
}
ll qpow(ll a, ll b, ll mod) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      ans = (ans * a) % mod;
    b >>= 1;
    a = (a * a) % mod;
  }
  return ans;
}

struct node {
  int x, y, d;
  bool operator<(const node &b) const { return d > b.d; }
};

int dis[400][400];
char s[400][400];
int n, m, fs, ft, es, et;
bool is(int x, int y) {
  return x >= 1 && x <= n && y >= 1 && y <= m && s[x][y] == '.';
}
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
int tx[] = {-2, -2, -2, -2, -2, -1, -1, -1, -1, -1, 0, 0,
            0,  0,  1,  1,  1,  1,  1,  2,  2,  2,  2, 2};
int ty[] = {-2, -1, 0,  1,  2, -2, -1, 0,  1,  2, -2, -1,
            1,  2,  -2, -1, 0, 1,  2,  -2, -1, 0, 1,  2};
void dij() {
  priority_queue<node> q;
  dis[fs][ft] = 0;
  q.push({fs, ft, 0});
  while (!q.empty()) {
    node tmp = q.top();
    q.pop();
    int x = tmp.x, y = tmp.y, d = tmp.d;
    if (d > dis[x][y])
      continue;
    int nx, ny;
    for (int i = 0; i < 3; ++i) {
      nx = x + dx[i];
      ny = y + dy[i];
      if (is(nx, ny) && dis[nx][ny] > dis[x][y]) {
        dis[nx][ny] = dis[x][y];
        q.push({nx, ny, dis[nx][ny]});
      }
    }
    for (int i = 0; i < 24; ++i) {
      nx = x + tx[i];
      ny = y + ty[i];
      if (is(nx, ny) && dis[nx][ny] > dis[x][y] + 1) {
        dis[nx][ny] = dis[x][y] + 1;
        q.push({nx, ny, dis[nx][ny]});
      }
    }
  }
}
int main() {
#ifdef local
  freopen("in.txt", "r", stdin);
#endif // local
  IOS;
  cout.tie(0);
  cin >> n >> m;
  cin >> fs >> ft;
  cin >> es >> et;
  rep1(i, n) cin >> (s[i] + 1);
  mst(dis, inf);
  dij();
  if (dis[es][et] == inf)
    cout << -1 << endl;
  else
    cout << dis[es][et] << endl;
  return 0;
}