Problem p02586 (C++) — buggy submission, verdict: Time Limit Exceeded

// #include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> p;
const int INF = 1e9;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1},
          Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)                                                               \\
  cout << #v << ":";                                                           \\
  for (auto x : v) {                                                           \\
    cout << x << ' ';                                                          \\
  }                                                                            \\
  cout << endl;
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
// cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//-std=gnu++17
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll rr, cc, k;
  cin >> rr >> cc >> k;
  vector<vector<ll>> m(rr, vector<ll>(cc, 0));
  rep(i, k) {
    ll temp, temp1, temp2;
    cin >> temp >> temp1 >> temp2;
    temp--;
    temp1--;
    m[temp][temp1] = temp2;
  }
  vector<vector<vector<ll>>> dp(rr, vector<vector<ll>>(cc, vector<ll>(4, 0)));
  rep(i, rr) {
    rep(j, cc) {
      rep(h, 4) {
        if (i + 1 < rr) {
          if (h != 3)
            chmax(dp[i + 1][j][0], dp[i][j][h] + m[i][j]);
          else
            chmax(dp[i + 1][j][0], dp[i][j][h]);
        }
        if (j + 1 < cc) {
          chmax(dp[i][j + 1][h], dp[i][j][h]);
          if (h != 3 && m[i][j] != 0)
            chmax(dp[i][j + 1][h + 1], dp[i][j][h] + m[i][j]);
        }
      }
    }
  }
  ll ans = 0;
  rep(i, 4) {
    if (i == 3)
      chmax(ans, dp[rr - 1][cc - 1][i]);
    else {
      chmax(ans, dp[rr - 1][cc - 1][i] + m[rr - 1][cc - 1]);
    }
  }
  cout << ans << "\\n";
}


Error: TLE

Fixed submission:

// #include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 1e9;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1},
          Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)                                                               \\
  cout << #v << ":";                                                           \\
  for (auto x : v) {                                                           \\
    cout << x << ' ';                                                          \\
  }                                                                            \\
  cout << endl;
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
// cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//-std=gnu++17
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
// ダイクストラ
// LINFにしてあるよ
struct edge {
  ll to, cost;
};
typedef pair<ll, ll> P;
struct graph {
  ll V;
  vector<vector<edge>> G;
  vector<ll> d;
  // vector<ll> count;経路の本数
  // vector<ll> prev; // prev[v] := v から復元できる辺たち
  graph(ll n) { init(n); }

  void init(ll n) {
    V = n;
    G.resize(V);
    d.resize(V);
    // count.resize(V);
    rep(i, V) {
      d[i] = LINF;
      // count[i] = 0;
    }
  }

  void add_edge(ll s, ll t, ll cost) {
    edge e;
    e.to = t, e.cost = cost;
    G[s].push_back(e);
  }

  void dijkstra(ll s) {
    rep(i, V) {
      d[i] = LINF;
      // count[i] = 0;
    }
    d[s] = 0;
    // count[s] = 1;
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, s));
    while (!que.empty()) {
      P p = que.top();
      que.pop();
      ll v = p.second;
      if (d[v] < p.first)
        continue;
      for (auto e : G[v]) {
        if (d[e.to] > d[v] + e.cost) {
          d[e.to] = d[v] + e.cost;
          que.push(P(d[e.to], e.to));
          // count[e.to] = count[v];
          //  復元のための
          // prev[e.to]=v;
        }
        /*
else if (d[e.to] == d[v] + e.cost)
        {
            count[e.to] += count[v];
            count[e.to] %= MOD;
        }
        */
      }
    }
  }
};
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll rr, cc, k;
  cin >> rr >> cc >> k;
  vector<ll> r(k), c(k), v(k);
  rep(i, k) cin >> r[i] >> c[i] >> v[i];
  graph g(rr * cc * 4);
  rep(i, rr) {
    rep(j, cc) {
      rep(h, 4) {
        if (i + 1 < rr) {
          g.add_edge(i * cc + j + (rr * cc) * h, (i + 1) * cc + j, 0);
        }
        if (j + 1 < cc) {
          g.add_edge(i * cc + j + (rr * cc) * h, i * cc + j + 1 + (rr * cc) * h,
                     0);
        }
      }
    }
  }
  g.add_edge(rr * cc - 1 + 0 * (rr * cc), rr * cc - 1 + 1 * (rr * cc), 0);
  g.add_edge(rr * cc - 1 + 1 * (rr * cc), rr * cc - 1 + 2 * (rr * cc), 0);
  g.add_edge(rr * cc - 1 + 2 * (rr * cc), rr * cc - 1 + 3 * (rr * cc), 0);
  rep(i, k) {
    r[i]--;
    c[i]--;
    rep(j, 3) {
      if (r[i] + 1 < rr)
        g.add_edge(r[i] * cc + c[i] + j * (rr * cc), (r[i] + 1) * cc + c[i],
                   -v[i]);
      if (c[i] + 1 < cc)
        g.add_edge(r[i] * cc + c[i] + j * (rr * cc),
                   (r[i]) * cc + c[i] + 1 + (j + 1) * (rr * cc), -v[i]);
      if (r[i] == rr - 1 && c[i] == cc - 1) {
        g.add_edge(r[i] * cc + c[i] + 2 * (rr * cc),
                   (r[i]) * cc + c[i] + (3) * (rr * cc), -v[i]);
      }
    }
  }
  g.dijkstra(0);
  cout << -g.d[rr * cc * 4 - 1] << "\\n";
  /*
  rep(i, rr)
  {
      rep(j, cc)
      {
          rep(h, 4)
          {
              cout << i << " " << j << " " << h << "\\n";
              cout << g.d[i * cc + j + h * cc * rr] << "\\n";
          }
      }
  }
  */
}