Problem p02581 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<P, ll> T;
typedef pair<long double, ll> Ps;
typedef pair<ll, bool> Pb;

const ll INF = 1e18;
const ll fact_table = 3200008;
long double Pi = 3.1415926535897932384626;

priority_queue<ll> pql;
priority_queue<P> pqp;
priority_queue<P> bag;
// big priority queue
priority_queue<ll, vector<ll>, greater<ll>> pqls;
priority_queue<P, vector<P>, greater<P>> pqps;
// small priority queue
// top pop

ll dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
ll dy[8] = {0, 1, 0, -1, 1, -1, -1, 1};
// ↓,→,↑,←

#define endl "\\n"
#ifdef ENJAPMA
#undef endl
#endif

#define p(x) cout << x << endl;
#define el cout << endl;
#define pe(x) cout << x << " ";
#define ps(x) cout << fixed << setprecision(25) << x << endl;
#define pu(x) cout << (x);
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define CLEAR(a) a = decltype(a)();
#define pc(x) cout << x << ",";
#define rep(i, n) for (ll i = 0; i < (n); i++)

// const ll mod = 998244353ll;
const ll mod = 1000000007ll;

ll mypow(ll a, ll b, ll mod) {
  ll x = 1;
  while (b) {
    while (!(b & 1)) {
      (a *= a) %= mod;
      b >>= 1;
    }
    (x *= a) %= mod;
    b--;
  }
  return x;
}
void YES(bool cond) {
  if (cond) {
    p("YES");
  } else {
    p("NO");
  }
  return;
}
void Yes(bool cond) {
  if (cond) {
    p("Yes");
  } else {
    p("No");
  }
  return;
}
void line() {
  p("--------------------");
  return;
}

/*
ll fact[fact_table + 5], rfact[fact_table + 5];

void c3_init() {
    fact[0] = rfact[0] = 1;
    for (ll i = 1; i <= fact_table; i++) {
        fact[i] = (fact[i - 1] * i) % mod;
    }
    rfact[fact_table] = mypow(fact[fact_table], mod - 2, mod);
    for (ll i = fact_table; i >= 1; i--) {
        rfact[i - 1] = rfact[i] * i;
        rfact[i - 1] %= mod;
    }
    return;
}
ll c3(ll n, ll r) {
    return (((fact[n] * rfact[r]) % mod ) * rfact[n - r]) % mod;
}
*/
struct Timer {
  int64_t start;
  const int64_t CYCLES_PER_SEC = 2800000000;
  Timer() { reset(); }
  void reset() { start = getCycle(); }
  inline double get() { return (double)(getCycle() - start) / CYCLES_PER_SEC; }
  inline int64_t getCycle() {
    uint32_t low, high;
    __asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
    return ((int64_t)low) | ((int64_t)high << 32);
  }
};

bool multicase = false;

ll n, m, k, w, num, a, b, c, d, e, h, q, ans, sum, l;

typedef vector<ll> vec;
typedef vector<vector<ll>> mat;
string s[1005];
ll dp[2][2005][2005];
ll max_table[2005][2005];
ll all_max[2005];
vector<P> updated;

void update(ll time, ll a, ll b, ll value) {
  dp[time % 2][a][b] = dp[time % 2][b][a] = max(dp[time % 2][a][b], value);
  max_table[time][a] = max(max_table[time][a], value);
  max_table[time][b] = max(max_table[time][b], value);
  all_max[time] = max(all_max[time], dp[time % 2][a][b]);
  all_max[time] = max(all_max[time], all_max[time - 1]);
  updated.pb(P(a, b));
  updated.pb(P(b, a));
  return;
}

void solve() {
  cin >> n;
  vec x(3 * n);
  for (int i = 0; i < 3 * n; i++) {
    cin >> x[i];
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      dp[0][i][j] = dp[1][i][j] = -INF;
    }
    all_max[i] = -INF;
  }
  for (int i = 0; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      max_table[i][j] = -INF;
    }
  }
  dp[0][x[0]][x[1]] = 0;
  dp[0][x[1]][x[0]] = 0;
  dp[1][x[0]][x[1]] = 0;
  dp[1][x[1]][x[0]] = 0;
  all_max[0] = 0;
  all_max[1] = 0;
  max_table[0][x[0]] = max_table[0][x[1]] = 0;
  max_table[1][x[0]] = max_table[1][x[1]] = 0;
  /*
  for(int i=1;i<=n;i++){
      for(int j=1;j<=n;j++){
          pe(dp[0][i][j]);
      }
      el;
  }
  */
  ll bonus = 0;
  for (int i = 0; i < n - 1; i++) {
    vec y(3);
    y[0] = x[2 + 3 * i], y[1] = x[3 + 3 * i], y[2] = x[4 + 3 * i];
    sort(y.begin(), y.end());
    a = y[0], b = y[1], c = y[2];
    if (a == b && b == c) {
      bonus++;
    } else if (a < b && b < c) {
      update(i + 1, a, b, max(dp[i % 2][c][c] + 1, all_max[i]));
      update(i + 1, b, c, max(dp[i % 2][a][a] + 1, all_max[i]));
      update(i + 1, a, c, max(dp[i % 2][b][b] + 1, all_max[i]));
      for (int j = 1; j <= n; j++) {
        // 片方がjであるようなものの最大値を持ってくる
        ll maxi = max_table[i][j];
        update(i + 1, a, j, maxi);
        update(i + 1, b, j, maxi);
        update(i + 1, c, j, maxi);
      }
    } else if (a == b && b < c) {
      // (a, a, c)

      update(i + 1, a, b, max(dp[i % 2][c][c] + 1, all_max[i]));
      update(i + 1, b, c, max(dp[i % 2][a][a] + 1, all_max[i]));
      update(i + 1, a, c, max(dp[i % 2][b][b] + 1, all_max[i]));
      // (a, c)を使う場合
      for (int j = 1; j <= n; j++) {
        ll maxi = max_table[i][j];
        update(i + 1, a, j, maxi);
      }

      // (a, a)を使う場合
      for (int j = 1; j <= n; j++) {
        // (a, j) -> (c, j) への遷移
        update(i + 1, c, j, dp[i % 2][a][j] + 1);
      }

      for (int j = 1; j <= n; j++) {
        // (*, j) -> (c, j) への遷移
        ll maxi = max_table[i][j];
        update(i + 1, c, j, maxi);
      }
    } else if (a < b && b == c) {
      update(i + 1, a, b, max(dp[i % 2][c][c] + 1, all_max[i]));
      update(i + 1, b, c, max(dp[i % 2][a][a] + 1, all_max[i]));
      update(i + 1, a, c, max(dp[i % 2][b][b] + 1, all_max[i]));
      for (int j = 1; j <= n; j++) {
        ll maxi = max_table[i][j];
        update(i + 1, b, j, maxi);
      }
      for (int j = 1; j <= n; j++) {
        update(i + 1, a, j, dp[i % 2][c][j] + 1);
      }
      for (int j = 1; j <= n; j++) {
        ll maxi = max_table[i][j];
        update(i + 1, a, j, maxi);
      }
    }
    for (auto u : updated) {
      int a = u.first, b = u.second;
      dp[i % 2][a][b] = max(dp[i % 2][a][b], dp[(i + 1) % 2][a][b]);
    }
    for (int j = 1; j <= n; j++) {
      max_table[i % 2][j] = max_table[(i + 1) % 2][j];
    }
    all_max[i + 2] = all_max[i + 1];
    updated.clear();
    /*
    line();
    for(int j=1;j<=n;j++){
        for(int k=1;k<=n;k++){
            pe(dp[(i+1)%2][j][k]);
        }
        el;
    }
    line();
    */
  }
  ll last = x.back();
  all_max[n - 1] = max(all_max[n - 1], dp[(n - 1) % 2][last][last] + 1);
  p(all_max[n - 1] + bonus);

  return;
}

int main() {
  // init();
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll q, testcase = 1;
  if (multicase) {
    cin >> q;
  } else {
    q = 1;
  }
  while (q--) {
    // pu("Case ");pu("#");pu(testcase);pu(": ");
    solve();
    testcase++;
  }
  // solve();
  return 0;
}


Error: -11

Fixed submission:

#include <bits/stdc++.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<P, ll> T;
typedef pair<long double, ll> Ps;
typedef pair<ll, bool> Pb;

const ll INF = 1e18;
const ll fact_table = 3200008;
long double Pi = 3.1415926535897932384626;

priority_queue<ll> pql;
priority_queue<P> pqp;
priority_queue<P> bag;
// big priority queue
priority_queue<ll, vector<ll>, greater<ll>> pqls;
priority_queue<P, vector<P>, greater<P>> pqps;
// small priority queue
// top pop

ll dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
ll dy[8] = {0, 1, 0, -1, 1, -1, -1, 1};
// ↓,→,↑,←

#define endl "\\n"
#ifdef ENJAPMA
#undef endl
#endif

#define p(x) cout << x << endl;
#define el cout << endl;
#define pe(x) cout << x << " ";
#define ps(x) cout << fixed << setprecision(25) << x << endl;
#define pu(x) cout << (x);
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define CLEAR(a) a = decltype(a)();
#define pc(x) cout << x << ",";
#define rep(i, n) for (ll i = 0; i < (n); i++)

// const ll mod = 998244353ll;
const ll mod = 1000000007ll;

ll mypow(ll a, ll b, ll mod) {
  ll x = 1;
  while (b) {
    while (!(b & 1)) {
      (a *= a) %= mod;
      b >>= 1;
    }
    (x *= a) %= mod;
    b--;
  }
  return x;
}
void YES(bool cond) {
  if (cond) {
    p("YES");
  } else {
    p("NO");
  }
  return;
}
void Yes(bool cond) {
  if (cond) {
    p("Yes");
  } else {
    p("No");
  }
  return;
}
void line() {
  p("--------------------");
  return;
}

/*
ll fact[fact_table + 5], rfact[fact_table + 5];

void c3_init() {
    fact[0] = rfact[0] = 1;
    for (ll i = 1; i <= fact_table; i++) {
        fact[i] = (fact[i - 1] * i) % mod;
    }
    rfact[fact_table] = mypow(fact[fact_table], mod - 2, mod);
    for (ll i = fact_table; i >= 1; i--) {
        rfact[i - 1] = rfact[i] * i;
        rfact[i - 1] %= mod;
    }
    return;
}
ll c3(ll n, ll r) {
    return (((fact[n] * rfact[r]) % mod ) * rfact[n - r]) % mod;
}
*/
struct Timer {
  int64_t start;
  const int64_t CYCLES_PER_SEC = 2800000000;
  Timer() { reset(); }
  void reset() { start = getCycle(); }
  inline double get() { return (double)(getCycle() - start) / CYCLES_PER_SEC; }
  inline int64_t getCycle() {
    uint32_t low, high;
    __asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
    return ((int64_t)low) | ((int64_t)high << 32);
  }
};

bool multicase = false;

ll n, m, k, w, num, a, b, c, d, e, h, q, ans, sum, l;

typedef vector<ll> vec;
typedef vector<vector<ll>> mat;

ll dp[500][500][500];

void solve() {
  cin >> n;
  assert(n <= 300);
  vec x(3 * n);
  for (int i = 0; i < 3 * n; i++) {
    cin >> x[i];
  }
  for (int i = 0; i < n; i++) {
    for (int j = 1; j <= n; j++) {
      for (int k = 1; k <= n; k++) {
        dp[i][j][k] = -INF;
      }
    }
  }
  dp[0][x[0]][x[1]] = dp[0][x[1]][x[0]] = 0;
  int bonus = 0;
  for (int i = 0; i < n - 1; i++) {
    // time: i -> i + 1
    vec y;
    for (int j = 1; j <= n; j++) {
      for (int k = 1; k <= n; k++) {
        y.clear();
        y.pb(j);
        y.pb(k);
        y.pb(x[3 * i + 2]);
        y.pb(x[3 * i + 3]);
        y.pb(x[3 * i + 4]);
        sort(y.begin(), y.end());
        for (int u1 = 0; u1 < 5; u1++) {
          for (int u2 = u1 + 1; u2 < 5; u2++) {
            for (int u3 = u2 + 1; u3 < 5; u3++) {
              int gain = (y[u1] == y[u2] && y[u2] == y[u3]) ? 1 : 0;
              vec unuse;
              for (int ii = 0; ii < 5; ii++) {
                if (u1 != ii && u2 != ii && u3 != ii)
                  unuse.pb(y[ii]);
              }
              dp[i + 1][unuse[0]][unuse[1]] =
                  max(dp[i + 1][unuse[0]][unuse[1]], dp[i][j][k] + gain);
            }
          }
        }
      }
    }
  }
  ll ans = 0;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      int gain = 0;
      if (i == j && j == x[3 * n - 1])
        gain = 1;
      ans = max(dp[n - 1][i][j] + gain, ans);
    }
  }
  p(ans);
  return;
}

int main() {
  // init();
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll q, testcase = 1;
  if (multicase) {
    cin >> q;
  } else {
    q = 1;
  }
  while (q--) {
    // pu("Case ");pu("#");pu(testcase);pu(": ");
    solve();
    testcase++;
  }
  // solve();
  return 0;
}