Problem p02586 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define REP(a, b) for (int a = 0; a < (b); ++a)
#define REP1(i, n) for (int i = 1; i <= (n); ++i)
#define debug(x) cerr << #x << ": " << x << '\\n'
#define all(x) (x).begin(), (x).end()
#define YES() printf("YES\\n")
#define NO() printf("NO\\n")
#define isYES(x) printf("%s\\n", (x) ? "YES" : "NO")
#define Yes() printf("Yes\\n")
#define No() printf("No\\n")
#define isYes(x) printf("%s\\n", (x) ? "Yes" : "No")
#define isPossible(x) printf("%s\\n", (x) ? "Possible" : "Impossible")
#define SZ(x) ((int)(x).size())
#define pb push_back
#define mp make_pair
// #define INF (1<<29)

const long long INF = 1LL << 50;

#define Sp(p) cout << setprecision(25) << fixed << p << endl
#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define vs vector<string>
#define pii pair<int, int>
#define pis pair<int, string>
#define psi pair<string, int>
#define pll pair<ll, ll>
#define pie 3.14159265358979323846
using namespace std;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
typedef pair<int, P> PP;
typedef pair<ll, LP> LPP;
template <class T = int> T in() {
  T x;
  cin >> x;
  return (x);
}
template <class T> void print(T &x) { cout << x << '\\n'; }

const int MOD = (int)1e9 + 7;
// const int mod =(int)998244353;
const int mod = (int)1e9 + 7;

const int MAX = 510000;
ll fac[MAX], finv[MAX], inv[MAX];
void COMint() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
ll COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
ll gcd(ll a, ll b) {
  if (a < 0)
    a = -a;
  if (b < 0)
    b = -b;
  if (b == 0)
    return a;
  if (a > b) {
    swap(a, b);
  }
  return gcd(a, b % a);
}
ll lcm(ll a, ll b) {
  if (a < 0)
    a = -a;
  if (b < 0)
    b = -b;
  ll g;
  g = gcd(a, b);
  return b / g * a;
}
bool compare_by_b(pair<int, int> a, pair<int, int> b) {
  if (a.second != b.second) {
    return a.second < b.second;
  } else {
    return a.first < b.first;
  }
}
bool compare_by_a(pair<int, int> a, pair<int, int> b) {
  if (a.first != b.first) {
    return a.first < b.first;
  } else {
    return a.second < b.second;
  }
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
ll RS(ll N, ll P) {
  if (P == 0) {
    return 1;
  } else {
    if (P % 2 == 0) {
      ll t = RS(N, P / 2);
      return t * t;
    } else {
      return N * RS(N, P - 1);
    }
  }
}
int d[3005][3005];
ll dp[3005][3005][4];
int main() {
  ios::sync_with_stdio(false);
  int R, C, N;
  cin >> R >> C >> N;
  REP(i, N) {
    int r, c, v;
    cin >> r >> c >> v;
    d[r - 1][c - 1] = v;
  }
  REP(i, R) REP(j, C) {
    for (int k = 2; k >= 0; k--) {
      chmax(dp[i][j][k + 1], dp[i][j][k] + d[i][j]);
    }
    REP(k, 4) {
      chmax(dp[i + 1][j][0], dp[i][j][k]);
      chmax(dp[i][j + 1][k], dp[i][j][k]);
    }
  }
  ll ans = 0;
  REP(k, 4) chmax(ans, dp[R - 1][C - 1][k]);
  cout << ans << endl;
  return 0;
}


Error: 0

Fixed submission:

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define REP(a, b) for (int a = 0; a < (b); ++a)
#define REP1(i, n) for (int i = 1; i <= (n); ++i)
#define debug(x) cerr << #x << ": " << x << '\\n'
#define all(x) (x).begin(), (x).end()
#define YES() printf("YES\\n")
#define NO() printf("NO\\n")
#define isYES(x) printf("%s\\n", (x) ? "YES" : "NO")
#define Yes() printf("Yes\\n")
#define No() printf("No\\n")
#define isYes(x) printf("%s\\n", (x) ? "Yes" : "No")
#define isPossible(x) printf("%s\\n", (x) ? "Possible" : "Impossible")
#define SZ(x) ((int)(x).size())
#define pb push_back
#define mp make_pair
// #define INF (1<<29)

const long long INF = 1LL << 50;

#define Sp(p) cout << setprecision(25) << fixed << p << endl
#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define vs vector<string>
#define pii pair<int, int>
#define pis pair<int, string>
#define psi pair<string, int>
#define pll pair<ll, ll>
#define pie 3.14159265358979323846
using namespace std;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
typedef pair<int, P> PP;
typedef pair<ll, LP> LPP;
template <class T = int> T in() {
  T x;
  cin >> x;
  return (x);
}
template <class T> void print(T &x) { cout << x << '\\n'; }

const int MOD = (int)1e9 + 7;
// const int mod =(int)998244353;
const int mod = (int)1e9 + 7;

const int MAX = 510000;
ll fac[MAX], finv[MAX], inv[MAX];
void COMint() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
ll COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
ll gcd(ll a, ll b) {
  if (a < 0)
    a = -a;
  if (b < 0)
    b = -b;
  if (b == 0)
    return a;
  if (a > b) {
    swap(a, b);
  }
  return gcd(a, b % a);
}
ll lcm(ll a, ll b) {
  if (a < 0)
    a = -a;
  if (b < 0)
    b = -b;
  ll g;
  g = gcd(a, b);
  return b / g * a;
}
bool compare_by_b(pair<int, int> a, pair<int, int> b) {
  if (a.second != b.second) {
    return a.second < b.second;
  } else {
    return a.first < b.first;
  }
}
bool compare_by_a(pair<int, int> a, pair<int, int> b) {
  if (a.first != b.first) {
    return a.first < b.first;
  } else {
    return a.second < b.second;
  }
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
ll RS(ll N, ll P) {
  if (P == 0) {
    return 1;
  } else {
    if (P % 2 == 0) {
      ll t = RS(N, P / 2);
      return t * t;
    } else {
      return N * RS(N, P - 1);
    }
  }
}
int main() {
  ios::sync_with_stdio(false);
  int R, C, K;
  cin >> R >> C >> K;
  map<pair<int, int>, int> m;
  REP(i, K) {
    int r, c, v;
    cin >> r >> c >> v;
    m[mp(r, c)] = v;
  }
  ll dp[R + 2][C + 2][4];
  REP(i, R + 2) REP(j, C + 2) REP(k, 4) dp[i][j][k] = 0;
  // 1行目R=1で初期化
  REP1(ir, R) {
    REP1(ic, C) {
      REP(i, 3) {
        int j = 2 - i;
        if (m[mp(ir, ic)] > 0) {
          dp[ir][ic][j + 1] =
              max(dp[ir][ic][j + 1], dp[ir][ic][j] + m[mp(ir, ic)]);
        }
      }
      REP(i, 4) {
        dp[ir + 1][ic][0] = max(dp[ir + 1][ic][0], dp[ir][ic][i]);
        dp[ir][ic + 1][i] = max(dp[ir][ic + 1][i], dp[ir][ic][i]);
      }
    }
  }
  ll ans = 0;
  REP(i, 4) ans = max(ans, dp[R][C][i]);
  cout << ans << endl;

  return 0;
}