Problem p02644 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<P, ll> T;
typedef pair<long double, ll> Ps;
typedef pair<ll, bool> Pb;

const ll INF = 1e18;
const ll fact_table = 3200008;
long double Pi = 3.1415926535897932384626;

priority_queue<ll> pql;
priority_queue<P> pqp;
priority_queue<P> bag;
// big priority queue
priority_queue<ll, vector<ll>, greater<ll>> pqls;
priority_queue<P, vector<P>, greater<P>> pqps;
// small priority queue
// top pop

ll dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
ll dy[8] = {0, 1, 0, -1, 1, -1, -1, 1};
char dir[] = "DRUL";
// ↓,→,↑,←

#define endl "\\n"
#ifdef ENJAPMA
#undef endl
#endif
#define p(x) cout << x << endl;
#define el cout << endl;
#define pe(x) cout << x << " ";
#define ps(x) cout << fixed << setprecision(25) << x << endl;
#define pu(x) cout << (x);
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define CLEAR(a) a = decltype(a)();
#define pc(x) cout << x << ",";
#define rep(i, n) for (ll i = 0; i < (n); i++)

// const ll mod = 998244353ll;
const ll mod = 1000000007ll;

ll mypow(ll a, ll b, ll mod) {
  ll x = 1;
  while (b) {
    while (!(b & 1)) {
      (a *= a) %= mod;
      b >>= 1;
    }
    (x *= a) %= mod;
    b--;
  }
  return x;
}
void YES(bool cond) {
  if (cond) {
    p("YES");
  } else {
    p("NO");
  }
  return;
}
void Yes(bool cond) {
  if (cond) {
    p("Yes");
  } else {
    p("No");
  }
  return;
}

ll line_count = 0;

void line() {

  line_count++;
  string s = (line_count % 2) ? "v-v-v-v-v-v-v-v-v-v" : "^-^-^-^-^-^-^-^-^-^";
  cout << endl << s << endl << endl;
}

/*
ll fact[fact_table + 5],rfact[fact_table + 5];

void c3_init(){
    fact[0] = rfact[0] = 1;
    for(ll i=1; i<=fact_table; i++){
        fact[i] = (fact[i-1]*i) % mod;
    }
    rfact[fact_table] = mypow(fact[fact_table],mod - 2, mod);
    for(ll i=fact_table; i>=1; i--){
       rfact[i-1] = rfact[i] * i;
       rfact[i-1] %= mod;
    }
    return;}
ll c3(ll n,ll r){
    return (((fact[n] * rfact[r]) % mod ) * rfact[n-r]) % mod;}
*/

bool multicase = false;

ll n, m, k, num, a, b, c, d, e, h, q, ans, sum;
string s;

typedef vector<ll> vec;
typedef vector<vector<ll>> mat;

void solve() {
  ll h, w;
  cin >> h >> w >> k;
  ll sx, sy, gx, gy;
  cin >> sx >> sy >> gx >> gy;
  sx--;
  sy--;
  gx--;
  gy--;
  mat dp(h, vec(w, 0));
  for (int i = 0; i < h; i++) {
    string s;
    cin >> s;
    for (int j = 0; j < w; j++) {
      if (s[j] == '@')
        dp[i][j] = 1;
    }
  }
  mat cost(h, vec(w, INF));
  queue<P> q;
  q.push(P(sx, sy));
  cost[sx][sy] = 0;

  while (q.size()) {
    P v = q.front();
    q.pop();

    if (v.first == gx && v.second == gy)
      break;

    for (int i = 0; i < 4; i++) {
      int nx = v.first, ny = v.second;
      for (int j = 1; j <= k; j++) {
        nx += dx[i], ny += dy[i];
        if (nx < 0 || h <= nx || ny < 0 || w <= ny)
          break;
        if (dp[nx][ny] == 1)
          break;
        if (cost[nx][ny] == cost[v.first][v.second])
          break;
        if (cost[nx][ny] != INF)
          continue;

        q.push(P(nx, ny));
        cost[nx][ny] = cost[v.first][v.second] + 1;
      }
    }
  }

  ll ans = cost[gx][gy];

  if (ans == INF) {
    p(-1);
  } else {
    p(ans);
  }

  return;
}

int main() {
  // init();
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll q, testcase = 1;
  if (multicase) {
    cin >> q;
  } else {
    q = 1;
  }
  while (q--) {
    // pu("Case ");pu("#");pu(testcase);pu(": ");
    solve();
    testcase++;
  }
  // solve();
  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<P, ll> T;
typedef pair<long double, ll> Ps;
typedef pair<ll, bool> Pb;

const ll INF = 1e18;
const ll fact_table = 3200008;
long double Pi = 3.1415926535897932384626;

priority_queue<ll> pql;
priority_queue<P> pqp;
priority_queue<P> bag;
// big priority queue
priority_queue<ll, vector<ll>, greater<ll>> pqls;
priority_queue<P, vector<P>, greater<P>> pqps;
// small priority queue
// top pop

ll dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
ll dy[8] = {0, 1, 0, -1, 1, -1, -1, 1};
char dir[] = "DRUL";
// ↓,→,↑,←

#define endl "\\n"
#ifdef ENJAPMA
#undef endl
#endif
#define p(x) cout << x << endl;
#define el cout << endl;
#define pe(x) cout << x << " ";
#define ps(x) cout << fixed << setprecision(25) << x << endl;
#define pu(x) cout << (x);
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define CLEAR(a) a = decltype(a)();
#define pc(x) cout << x << ",";
#define rep(i, n) for (ll i = 0; i < (n); i++)

// const ll mod = 998244353ll;
const ll mod = 1000000007ll;

ll mypow(ll a, ll b, ll mod) {
  ll x = 1;
  while (b) {
    while (!(b & 1)) {
      (a *= a) %= mod;
      b >>= 1;
    }
    (x *= a) %= mod;
    b--;
  }
  return x;
}
void YES(bool cond) {
  if (cond) {
    p("YES");
  } else {
    p("NO");
  }
  return;
}
void Yes(bool cond) {
  if (cond) {
    p("Yes");
  } else {
    p("No");
  }
  return;
}

ll line_count = 0;

void line() {

  line_count++;
  string s = (line_count % 2) ? "v-v-v-v-v-v-v-v-v-v" : "^-^-^-^-^-^-^-^-^-^";
  cout << endl << s << endl << endl;
}

/*
ll fact[fact_table + 5],rfact[fact_table + 5];

void c3_init(){
    fact[0] = rfact[0] = 1;
    for(ll i=1; i<=fact_table; i++){
        fact[i] = (fact[i-1]*i) % mod;
    }
    rfact[fact_table] = mypow(fact[fact_table],mod - 2, mod);
    for(ll i=fact_table; i>=1; i--){
       rfact[i-1] = rfact[i] * i;
       rfact[i-1] %= mod;
    }
    return;}
ll c3(ll n,ll r){
    return (((fact[n] * rfact[r]) % mod ) * rfact[n-r]) % mod;}
*/

bool multicase = false;

ll n, m, k, num, a, b, c, d, e, h, q, ans, sum;
string s;

typedef vector<ll> vec;
typedef vector<vector<ll>> mat;

void solve() {
  ll h, w;
  cin >> h >> w >> k;
  ll sx, sy, gx, gy;
  cin >> sx >> sy >> gx >> gy;
  sx--;
  sy--;
  gx--;
  gy--;
  mat dp(h, vec(w, 0));
  for (int i = 0; i < h; i++) {
    string s;
    cin >> s;
    for (int j = 0; j < w; j++) {
      if (s[j] == '@')
        dp[i][j] = 1;
    }
  }
  mat cost(h, vec(w, INF));
  queue<P> q;
  q.push(P(sx, sy));
  cost[sx][sy] = 0;

  while (q.size()) {
    P v = q.front();
    q.pop();

    if (v.first == gx && v.second == gy)
      break;

    for (int i = 0; i < 4; i++) {
      for (int j = 1; j <= k; j++) {
        int nx = v.first + dx[i] * j, ny = v.second + dy[i] * j;
        if (nx < 0 || h <= nx || ny < 0 || w <= ny)
          break;
        if (dp[nx][ny] == 1)
          break;
        if (cost[nx][ny] != INF)
          continue;

        q.push(P(nx, ny));
        cost[nx][ny] = cost[v.first][v.second] + 1;
      }
    }
  }

  ll ans = cost[gx][gy];

  if (ans == INF) {
    p(-1);
  } else {
    p(ans);
  }

  return;
}

int main() {
  // init();
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll q, testcase = 1;
  if (multicase) {
    cin >> q;
  } else {
    q = 1;
  }
  while (q--) {
    // pu("Case ");pu("#");pu(testcase);pu(": ");
    solve();
    testcase++;
  }
  // solve();
  return 0;
}