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

#include <bits/stdc++.h>
// ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
// clock_t start=clock();clock_t
// end=clock();cout<<(double)(end-start)/CLOCKS_PER_SEC<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int, int> pii;
typedef pair<pii, int> ppii;
typedef pair<int, pii> pipi;
typedef pair<ll, ll> pll;
typedef pair<pll, ll> ppll;
typedef pair<ll, pll> plpl;
typedef pair<pii, pii> pippi;
typedef tuple<ll, ll, ll> tl;
typedef pair<double, double> pdd;
typedef vector<vector<ll>> mat;
ll mod = 1000000007;
ll mod2 = 998244353;
ll mod3 = 1000003;
ll mod4 = 998244853;
ll mod5 = 1000000009;
ll inf = 1LL << 61;
int iinf = 1 << 30;
double pi = 3.14159265358979323846;
double pi2 = pi / 2.0;
double eps = 1e-8;
#define rep(i, m, n) for (int i = m; i < n; i++)
#define rrep(i, n, m) for (ll i = n; i >= m; i--)
#define srep(itr, st) for (auto itr = st.begin(); itr != st.end(); itr++)
#define mrep(itr, mp) for (auto &itr : mp)
#define Max(a, b) a = max(a, b)
#define Min(a, b) a = min(a, b)
// #define endl "\\n"
int dh[4] = {1, 0, -1, 0};
int dw[4] = {0, 1, 0, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }

  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
#define umh unordered_map<int, int, custom_hash>
ll gcd(ll a, ll b) {
  if (a < 0)
    a = -a;
  if (b < 0)
    b = -b;
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  if (a % b == 0)
    return b;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) {
  ll c = gcd(a, b);
  return a * b / c;
}
ll Pow(ll n, ll k) {
  if (k < 0)
    return 0;
  ll ret = 1;
  ll now = n;
  while (k > 0) {
    if (k & 1)
      ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
ll beki(ll n, ll k, ll md) {
  ll ret = 1;
  ll now = n;
  now %= md;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
ll gyaku(ll n, ll md) { return beki(n, md - 2, md); }
ll popcount(ll n) {
  ll ret = 0;
  ll u = n;
  while (u > 0) {
    ret += u % 2;
    u /= 2;
  }
  return ret;
}
ll f(vector<ll> &v, ll x) {
  if (x >= v[0]) {
    v[2] = v[1];
    v[1] = v[0];
    v[0] = x;
  } else if (x >= v[1]) {
    v[2] = v[1];
    v[1] = x;
  } else if (x >= v[2]) {
    v[2] = x;
  }
  ll ret = 0;
  rep(i, 0, 3) ret += v[i];
  return ret;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ll h, w;
  cin >> h >> w;
  ll k;
  cin >> k;
  vector<pll> v[h];
  rep(i, 0, k) {
    ll a, b, c;
    cin >> a >> b >> c;
    a--;
    b--;
    v[a].push_back({b, c});
  }
  rep(i, 0, h) sort(v[i].begin(), v[i].end());
  ll dp[h + 1][w];
  rep(i, 0, h + 1) rep(j, 0, w) dp[i][j] = -inf;
  dp[0][0] = 0;
  rep(i, 0, h) {
    ll now = 0;
    ll maa = 0;
    rep(j, 0, w) {
      if (now == v[i].size()) {
        Max(dp[i + 1][j], dp[i][j]);
        continue;
      }
      if (now < v[i].size() && v[i][now].first > j) {
        Max(maa, dp[i][j]);
        Max(dp[i + 1][j], dp[i][j]);
      } else if (now < v[i].size() && v[i][now].first == j) {
        Max(maa, dp[i][j]);
        Max(dp[i + 1][j], dp[i][j]);
        vector<ll> vv = {0, 0, 0};
        rep(l, now, v[i].size()) {
          ll ne = v[i][l].first, co = v[i][l].second;
          Max(dp[i + 1][ne], maa + f(vv, co));
        }
        now++;
      }
    }
  }
  ll ans = 0;
  rep(i, 0, w) Max(ans, dp[h][i]);
  cout << ans << endl;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
// ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
// clock_t start=clock();clock_t
// end=clock();cout<<(double)(end-start)/CLOCKS_PER_SEC<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int, int> pii;
typedef pair<pii, int> ppii;
typedef pair<int, pii> pipi;
typedef pair<ll, ll> pll;
typedef pair<pll, ll> ppll;
typedef pair<ll, pll> plpl;
typedef pair<pii, pii> pippi;
typedef tuple<ll, ll, ll> tl;
typedef pair<double, double> pdd;
typedef vector<vector<ll>> mat;
ll mod = 1000000007;
ll mod2 = 998244353;
ll mod3 = 1000003;
ll mod4 = 998244853;
ll mod5 = 1000000009;
ll inf = 1LL << 61;
int iinf = 1 << 30;
double pi = 3.14159265358979323846;
double pi2 = pi / 2.0;
double eps = 1e-8;
#define rep(i, m, n) for (int i = m; i < n; i++)
#define rrep(i, n, m) for (ll i = n; i >= m; i--)
#define srep(itr, st) for (auto itr = st.begin(); itr != st.end(); itr++)
#define mrep(itr, mp) for (auto &itr : mp)
#define Max(a, b) a = max(a, b)
#define Min(a, b) a = min(a, b)
// #define endl "\\n"
int dh[4] = {1, 0, -1, 0};
int dw[4] = {0, 1, 0, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }

  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
#define umh unordered_map<int, int, custom_hash>
ll gcd(ll a, ll b) {
  if (a < 0)
    a = -a;
  if (b < 0)
    b = -b;
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  if (a % b == 0)
    return b;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) {
  ll c = gcd(a, b);
  return a * b / c;
}
ll Pow(ll n, ll k) {
  if (k < 0)
    return 0;
  ll ret = 1;
  ll now = n;
  while (k > 0) {
    if (k & 1)
      ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
ll beki(ll n, ll k, ll md) {
  ll ret = 1;
  ll now = n;
  now %= md;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
ll gyaku(ll n, ll md) { return beki(n, md - 2, md); }
ll popcount(ll n) {
  ll ret = 0;
  ll u = n;
  while (u > 0) {
    ret += u % 2;
    u /= 2;
  }
  return ret;
}
ll f(vector<ll> &v, ll x) {
  v.push_back(x);
  sort(v.begin(), v.end(), greater<ll>());
  v.resize(3);
  ll ret = 0;
  rep(i, 0, 3) ret += v[i];
  return ret;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ll h, w;
  cin >> h >> w;
  ll k;
  cin >> k;
  vector<pll> v[h];
  rep(i, 0, k) {
    ll a, b, c;
    cin >> a >> b >> c;
    a--;
    b--;
    v[a].push_back({b, c});
  }
  rep(i, 0, h) sort(v[i].begin(), v[i].end());
  ll dp[h + 1][w];
  rep(i, 0, h + 1) rep(j, 0, w) dp[i][j] = -inf;
  dp[0][0] = 0;
  rep(i, 0, h) {
    ll now = 0;
    rep(j, 0, w) {
      if (now < v[i].size() && v[i][now].first < j)
        now++;
      if (dp[i][j] == -inf)
        continue;
      vector<ll> vv = {0, 0, 0};
      Max(dp[i + 1][j], dp[i][j]);
      rep(l, now, v[i].size()) {
        ll ne = v[i][l].first, co = v[i][l].second;
        Max(dp[i + 1][ne], dp[i][j] + f(vv, co));
      }
    }
  }
  ll ans = 0;
  rep(i, 0, w) Max(ans, dp[h][i]);
  cout << ans << endl;
}