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

/**
 *    author:  otera
 **/
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

#define int long long
typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf = 1e9 + 7;
const ll INF = 1LL << 60;
const ll mod = 1e9 + 7;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(), c.end()
#define pb push_back
#define debug(x) cerr << #x << " = " << (x) << endl;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

void solve() {
  int r, c, k;
  cin >> r >> c >> k;
  static int a[3030][3030];
  rep(i, k) {
    int x, y, v;
    cin >> x >> y >> v;
    --x, --y;
    // mp[P{x, y}] = v;
    a[x][y] = v;
  }
  static int dp[3030][3030][4];
  // rep(i, 3030) rep(j, 3030) rep(k, 4) dp[i][j][k] = -INF;
  dp[0][0][0] = 0;
  rep(i, r) {
    rep(j, c) {
      rep(k, 4) {
        if (k < 3) {
          chmax(dp[i + 1][j][0], dp[i][j][k]);
          chmax(dp[i][j + 1][k], dp[i][j][k]);
          if (a[i][j] > 0)
            chmax(dp[i + 1][j][0], dp[i][j][k] + a[i][j]);
          if (a[i][j] > 0)
            chmax(dp[i][j + 1][k + 1], dp[i][j][k] + a[i][j]);
        } else {
          chmax(dp[i + 1][j][0], dp[i][j][k]);
          chmax(dp[i][j + 1][k], dp[i][j][k]);
        }
      }
    }
  }
  if (a[r - 1][c - 1] > 0) {
    per(k, 3) {
      chmax(dp[r - 1][c - 1][k + 1], dp[r - 1][c - 1][k] + a[r - 1][c - 1]);
    }
  }
  cout << *max_element(dp[r - 1][c - 1], dp[r - 1][c - 1] + 5) << endl;
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(10);
  // int t; cin >> t; rep(i, t)solve();
  solve();
  return 0;
}

Error: TLE

Fixed submission:

/**
 *    author:  otera
 **/
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

#define int long long
typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf = 1e9 + 7;
const ll INF = 1LL << 60;
const ll mod = 1e9 + 7;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(), c.end()
#define pb push_back
#define debug(x) cerr << #x << " = " << (x) << endl;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

void solve() {
  int r, c, k;
  cin >> r >> c >> k;
  map<P, int> mp;
  rep(i, k) {
    int x, y, v;
    cin >> x >> y >> v;
    --x, --y;
    mp[P{x, y}] = v;
  }
  static int dp[3030][3030][4];
  rep(i, 3030) rep(j, 3030) rep(k, 4) dp[i][j][k] = -INF;
  dp[0][0][0] = 0;
  rep(i, r) {
    rep(j, c) {
      rep(k, 4) {
        if (k < 3) {
          chmax(dp[i + 1][j][0], dp[i][j][k]);
          chmax(dp[i][j + 1][k], dp[i][j][k]);
          if (mp[{i, j}] > 0)
            chmax(dp[i + 1][j][0], dp[i][j][k] + mp[{i, j}]);
          if (mp[{i, j}] > 0)
            chmax(dp[i][j + 1][k + 1], dp[i][j][k] + mp[{i, j}]);
        } else {
          chmax(dp[i + 1][j][0], dp[i][j][k]);
          chmax(dp[i][j + 1][k], dp[i][j][k]);
        }
      }
    }
  }
  if (mp[{r - 1, c - 1}] > 0) {
    per(k, 3) {
      chmax(dp[r - 1][c - 1][k + 1], dp[r - 1][c - 1][k] + mp[{r - 1, c - 1}]);
    }
  }
  cout << *max_element(dp[r - 1][c - 1], dp[r - 1][c - 1] + 5) << endl;
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(10);
  // int t; cin >> t; rep(i, t)solve();
  solve();
  return 0;
}