Problem p03162 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const double EPS = 1e-9;
typedef vector<ll> vecl;
typedef pair<ll, ll> pairl;

template <typename T, typename U> using mapv = map<T, vector<U>>;

#define ALL(v) v.begin(), v.end()
#define REP(i, x, n) for (int i = x; i < n; i++)
#define rep(i, n) REP(i, 0, n)
template <class T, class C> void chmax(T &a, C b) { a > b ?: a = b; }
template <class T, class C> void chmin(T &a, C b) { a < b ?: a = b; }

#define MOD097 1000000007

///// For Debug

#define repi(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
// vector
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
// pair
template <typename T, typename U>
ostream &operator<<(ostream &os, pair<T, U> &pair_var) {
  os << "(" << pair_var.first << ", " << pair_var.second << ")";
  return os;
}
// vector
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
  os << "{";
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i] << (i + 1 == vec.size() ? "" : ", ");
  }
  os << "}";
  return os;
}
// map
template <typename T, typename U>
ostream &operator<<(ostream &os, map<T, U> &map_var) {
  os << "{";
  repi(itr, map_var) {
    os << *itr;
    itr++;
    if (itr != map_var.end())
      os << ", ";
    itr--;
  }
  os << "}";
  return os;
}
// set
template <typename T> ostream &operator<<(ostream &os, set<T> &set_var) {
  os << "{";
  repi(itr, set_var) {
    os << *itr;
    itr++;
    if (itr != set_var.end())
      os << ", ";
    itr--;
  }
  os << "}";
  return os;
}

#define DUMPOUT cerr

void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&...tail) {
  DUMPOUT << head;
  if (sizeof...(Tail) > 0) {
    DUMPOUT << ", ";
  }
  dump_func(std::move(tail)...);
}

// 提出時はコメントアウト
// #define LOCAL
#define DEBUG_

#ifndef LOCAL
#undef DEBUG_
#endif

#ifdef DEBUG_

#define DEB
#define dump(...)                                                              \
  DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                              \
          << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl  \
          << "    ",                                                           \
      dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)

#endif

//////////

struct ABC {
  ll a;
  ll b;
  ll c;
};

int main() {
#ifdef LOCAL
  ifstream in("../../Atcoder/input.txt");
  cin.rdbuf(in.rdbuf());
#endif

  ll N;
  cin >> N;
  vector<ABC> X(N);

  rep(i, N) {
    ll a, b, c;
    cin >> a >> b >> c;
    X[i] = {a, b, c};
  }

  vector<vecl> dp(N + 1, vecl(3, 0));
  rep(i, N) {
    auto x = X[i];
    ll a = x.a;
    ll b = x.b;
    ll c = x.c;

    chmax(dp[i + 1]['b'], max(dp[i]['a'] + b, dp[i]['c'] + b));
    chmax(dp[i + 1]['c'], max(dp[i]['a'] + c, dp[i]['b'] + c));
    chmax(dp[i + 1]['a'], max(dp[i]['b'] + a, dp[i]['c'] + a));
  }

  ll ans = 0;
  rep(i, 3) { ans = max(ans, dp[N]['a' + i]); }

  cout << ans << endl;

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const double EPS = 1e-9;
typedef vector<ll> vecl;
typedef pair<ll, ll> pairl;

template <typename T, typename U> using mapv = map<T, vector<U>>;

#define ALL(v) v.begin(), v.end()
#define REP(i, x, n) for (int i = x; i < n; i++)
#define rep(i, n) REP(i, 0, n)
template <class T, class C> void chmax(T &a, C b) { a > b ?: a = b; }
template <class T, class C> void chmin(T &a, C b) { a < b ?: a = b; }

#define MOD097 1000000007

///// For Debug

#define repi(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
// vector
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
// pair
template <typename T, typename U>
ostream &operator<<(ostream &os, pair<T, U> &pair_var) {
  os << "(" << pair_var.first << ", " << pair_var.second << ")";
  return os;
}
// vector
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
  os << "{";
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i] << (i + 1 == vec.size() ? "" : ", ");
  }
  os << "}";
  return os;
}
// map
template <typename T, typename U>
ostream &operator<<(ostream &os, map<T, U> &map_var) {
  os << "{";
  repi(itr, map_var) {
    os << *itr;
    itr++;
    if (itr != map_var.end())
      os << ", ";
    itr--;
  }
  os << "}";
  return os;
}
// set
template <typename T> ostream &operator<<(ostream &os, set<T> &set_var) {
  os << "{";
  repi(itr, set_var) {
    os << *itr;
    itr++;
    if (itr != set_var.end())
      os << ", ";
    itr--;
  }
  os << "}";
  return os;
}

#define DUMPOUT cerr

void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&...tail) {
  DUMPOUT << head;
  if (sizeof...(Tail) > 0) {
    DUMPOUT << ", ";
  }
  dump_func(std::move(tail)...);
}

// 提出時はコメントアウト
// #define LOCAL
#define DEBUG_

#ifndef LOCAL
#undef DEBUG_
#endif

#ifdef DEBUG_

#define DEB
#define dump(...)                                                              \
  DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                              \
          << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl  \
          << "    ",                                                           \
      dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)

#endif

//////////

struct ABC {
  ll a;
  ll b;
  ll c;
};

int main() {
#ifdef LOCAL
  ifstream in("../../Atcoder/input.txt");
  cin.rdbuf(in.rdbuf());
#endif

  ll N;
  cin >> N;
  vector<ABC> X(N);

  rep(i, N) {
    ll a, b, c;
    cin >> a >> b >> c;
    X[i] = {a, b, c};
  }

  vector<vecl> dp(N + 1, vecl(300, 0));
  rep(i, N) {
    auto x = X[i];
    ll a = x.a;
    ll b = x.b;
    ll c = x.c;

    chmax(dp[i + 1]['b'], max(dp[i]['a'] + b, dp[i]['c'] + b));
    chmax(dp[i + 1]['c'], max(dp[i]['a'] + c, dp[i]['b'] + c));
    chmax(dp[i + 1]['a'], max(dp[i]['b'] + a, dp[i]['c'] + a));
  }

  ll ans = 0;
  rep(i, 3) { ans = max(ans, dp[N]['a' + i]); }

  cout << ans << endl;

  return 0;
}