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

/*
これを入れて実行
g++ code.cpp
./a.out
 */

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <stdio.h>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

using namespace std;
typedef long long ll;
typedef long double ld;

int dy4[4] = {-1, 0, +1, 0};
int dx4[4] = {0, +1, 0, -1};
int dy8[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
int dx8[8] = {0, 1, 1, 1, 0, -1, -1, -1};

const long long INF = 1LL << 60;
const ll MOD = 1e9 + 7;

bool greaterSecond(const pair<int, int> &f, const pair<int, int> &s) {
  return f.second > s.second;
}

ll gcd(ll a, ll b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}

ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

ll conbinationMemo[100][100];

void cmemoInit() {
  rep(i, 100) {
    rep(j, 100) { conbinationMemo[i][j] = -1; }
  }
}

ll nCr(ll n, ll r) {
  if (conbinationMemo[n][r] != -1)
    return conbinationMemo[n][r];
  if (r == 0 || r == n) {
    return 1;
  } else if (r == 1) {
    return n;
  }
  return conbinationMemo[n][r] = (nCr(n - 1, r) + nCr(n - 1, r - 1));
}

ll nPr(ll n, ll r) {
  r = n - r;
  ll ret = 1;
  for (ll i = n; i >= r + 1; i--)
    ret *= i;
  return ret;
}
//-----------------------ここから-----------
int main(void) {
  ll h, w;
  cin >> h >> w;
  pair<ll, ll> c, d;
  cin >> c.first >> c.second;
  cin >> d.first >> d.second;
  c.first--;
  c.second--;
  d.first--;
  d.second--;

  vector<string> s(h);
  rep(i, h) cin >> s[i];
  ll ans = INF;
  priority_queue<pair<ll, pair<ll, ll>>, vector<pair<ll, pair<ll, ll>>>,
                 greater<pair<ll, pair<ll, ll>>>>
      q;
  vector<vector<ll>> dist(h, vector<ll>(w, INF));
  dist[c.first][c.second] = 0;
  q.push({0, c});
  while (!q.empty()) {
    pair<ll, ll> now = q.top().second;
    ll nowdist = q.top().first;
    q.pop();
    if (dist[now.first][now.second] < nowdist)
      continue;
    rep(i, 4) {
      pair<ll, ll> next;
      next.first = now.first + dx4[i];
      next.second = now.second + dy4[i];
      if (next.first < 0 || next.first >= h || next.second < 0 ||
          next.second >= w)
        continue;
      if (s[next.first][next.second] == '#')
        continue;
      if (dist[next.first][next.second] <= nowdist)
        continue;
      dist[next.first][next.second] = nowdist;
      if (next == d) {
        ans = min(ans, nowdist);
      }
      q.push({nowdist, next});
    }

    for (ll i = -2; i <= 2; i++) {
      for (ll j = -2; j <= 2; j++) {
        pair<ll, ll> next;
        next.first = now.first + i;
        next.second = now.second + j;
        if (next.first < 0 || next.first >= h || next.second < 0 ||
            next.second >= w)
          continue;
        if (s[next.first][next.second] == '#')
          continue;
        ll nextdist = nowdist + 1;
        if (dist[next.first][next.second] <= nextdist)
          continue;
        dist[next.first][next.second] = nextdist;
        if (next == d) {
          ans = min(ans, nextdist);
        }
        q.push({nextdist, next});
      }
    }
  }

  cout << (ans >= INF ? -1 : ans) << endl;
}

Error: TLE

Fixed submission:

/*
これを入れて実行
g++ code.cpp
./a.out
 */

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <stdio.h>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

using namespace std;
typedef long long ll;
typedef long double ld;

int dy4[4] = {-1, 0, +1, 0};
int dx4[4] = {0, +1, 0, -1};
int dy8[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
int dx8[8] = {0, 1, 1, 1, 0, -1, -1, -1};

const long long INF = 1LL << 60;
const ll MOD = 1e9 + 7;

bool greaterSecond(const pair<int, int> &f, const pair<int, int> &s) {
  return f.second > s.second;
}

ll gcd(ll a, ll b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}

ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

ll conbinationMemo[100][100];

void cmemoInit() {
  rep(i, 100) {
    rep(j, 100) { conbinationMemo[i][j] = -1; }
  }
}

ll nCr(ll n, ll r) {
  if (conbinationMemo[n][r] != -1)
    return conbinationMemo[n][r];
  if (r == 0 || r == n) {
    return 1;
  } else if (r == 1) {
    return n;
  }
  return conbinationMemo[n][r] = (nCr(n - 1, r) + nCr(n - 1, r - 1));
}

ll nPr(ll n, ll r) {
  r = n - r;
  ll ret = 1;
  for (ll i = n; i >= r + 1; i--)
    ret *= i;
  return ret;
}
//-----------------------ここから-----------
int main(void) {
  ll h, w;
  cin >> h >> w;
  pair<ll, ll> c, d;
  cin >> c.first >> c.second;
  cin >> d.first >> d.second;
  c.first--;
  c.second--;
  d.first--;
  d.second--;

  vector<string> s(h);
  rep(i, h) cin >> s[i];
  ll ans = INF;
  queue<pair<pair<ll, ll>, ll>> q;
  vector<vector<ll>> dist(h, vector<ll>(w, INF));
  dist[c.first][c.second] = 0;
  q.push({c, 0});
  while (!q.empty()) {
    pair<ll, ll> now = q.front().first;
    ll nowdist = q.front().second;
    q.pop();
    if (dist[now.first][now.second] < nowdist)
      continue;
    rep(i, 4) {
      pair<ll, ll> next;
      next.first = now.first + dx4[i];
      next.second = now.second + dy4[i];
      if (next.first < 0 || next.first >= h || next.second < 0 ||
          next.second >= w)
        continue;
      if (s[next.first][next.second] == '#')
        continue;
      if (dist[next.first][next.second] <= nowdist)
        continue;
      dist[next.first][next.second] = nowdist;
      if (next == d) {
        ans = min(ans, nowdist);
      }
      q.push({next, nowdist});
    }

    for (ll i = -2; i <= 2; i++) {
      for (ll j = -2; j <= 2; j++) {
        pair<ll, ll> next;
        next.first = now.first + i;
        next.second = now.second + j;
        if (next.first < 0 || next.first >= h || next.second < 0 ||
            next.second >= w)
          continue;
        if (s[next.first][next.second] == '#')
          continue;
        ll nextdist = nowdist + 1;
        if (dist[next.first][next.second] <= nextdist)
          continue;
        dist[next.first][next.second] = nextdist;
        if (next == d) {
          ans = min(ans, nextdist);
        }
        q.push({next, nextdist});
      }
    }
  }

  cout << (ans >= INF ? -1 : ans) << endl;
}