Problem p02589 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
#define MP make_pair
#define PB push_back
#define int long long
#define st first
#define nd second
#define rd third
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define RE(i, n) FOR(i, 1, n)
#define FORD(i, a, b) for (int i = (a); i >= (b); --i)
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define VAR(v, i) __typeof(i) v = (i)
#define FORE(i, c) for (VAR(i, (c).begin()); i != (c).end(); ++i)
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define __builtin_ctz __builtin_ctzll
#define __builtin_clz __builtin_clzll
#define __builtin_popcount __builtin_popcountll
using namespace std;
template <typename TH> void _dbg(const char *sdbg, TH h) {
  cerr << sdbg << "=" << h << "\\n";
}
template <typename TH, typename... TA>
void _dbg(const char *sdbg, TH h, TA... t) {
  while (*sdbg != ',') {
    cerr << *sdbg++;
  }
  cerr << "=" << h << ",";
  _dbg(sdbg + 1, t...);
}
#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#define debugv(x)                                                              \\
  {                                                                            \\
    {                                                                          \\
      cerr << #x << " = ";                                                     \\
      FORE(itt, (x)) cerr << *itt << ", ";                                     \\
      cerr << "\\n";                                                            \\
    }                                                                          \\
  }
#else
#define debug(...) (__VA_ARGS__)
#define debugv(x)
#define cerr                                                                   \\
  if (0)                                                                       \\
  cout
#endif
#define next ____next
#define prev ____prev
#define left ____left
#define hash ____hash
typedef long long ll;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VLL;
typedef vector<pair<int, int>> VPII;
typedef vector<pair<ll, ll>> VPLL;

template <class C> void mini(C &a4, C b4) { a4 = min(a4, b4); }
template <class C> void maxi(C &a4, C b4) { a4 = max(a4, b4); }
template <class T1, class T2>
ostream &operator<<(ostream &out, pair<T1, T2> pair) {
  return out << "(" << pair.first << ", " << pair.second << ")";
}
template <class A, class B, class C> struct Triple {
  A first;
  B second;
  C third;
  bool operator<(const Triple &t) const {
    if (st != t.st)
      return st < t.st;
    if (nd != t.nd)
      return nd < t.nd;
    return rd < t.rd;
  }
};
template <class T> void ResizeVec(T &, vector<int>) {}
template <class T> void ResizeVec(vector<T> &vec, vector<int> sz) {
  vec.resize(sz[0]);
  sz.erase(sz.begin());
  if (sz.empty()) {
    return;
  }
  for (T &v : vec) {
    ResizeVec(v, sz);
  }
}
typedef Triple<int, int, int> TIII;
template <class A, class B, class C>
ostream &operator<<(ostream &out, Triple<A, B, C> t) {
  return out << "(" << t.st << ", " << t.nd << ", " << t.rd << ")";
}
template <class T> ostream &operator<<(ostream &out, vector<T> vec) {
  out << "(";
  for (auto &v : vec)
    out << v << ", ";
  return out << ")";
}
template <class T> ostream &operator<<(ostream &out, set<T> vec) {
  out << "(";
  for (auto &v : vec)
    out << v << ", ";
  return out << ")";
}
template <class L, class R> ostream &operator<<(ostream &out, map<L, R> vec) {
  out << "(";
  for (auto &v : vec)
    out << v << ", ";
  return out << ")";
}

const int P[2] = {999999197, (int)1e9 + 7};
const int B[2] = {1234, 2345};

int32_t main() {

  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(10);
  cerr << fixed << setprecision(10);
  cin.tie(0);
  // double beg_clock = 1.0 * clock() / CLOCKS_PER_SEC;

  int n;
  cin >> n;
  map<PII, VI> cnt;
  vector<string> strs;
  RE(i, n) {
    string s;
    cin >> s;
    strs.PB(s);
    VI h(2);
    RE(j, SZ(s) - 1) {
      REP(tr, 2) { h[tr] = (h[tr] * B[tr] + s[j]) % P[tr]; }
    }
    auto &c = cnt[{h[0], h[1]}];
    if (c.empty()) {
      c.resize(26);
    }
    c[s[0] - 'a']++;
  }
  int res = 0;
  for (auto s : strs) {
    VPII sufs(SZ(s) + 1);
    REP(tr, 2) {
      int h = 0;
      int mul = 1;
      FORD(i, SZ(s) - 1, 1) {
        h = (h + mul * s[i]) % P[tr];
        mul = mul * B[tr] % P[tr];
        if (tr == 0) {
          sufs[i].st = h;
        } else {
          sufs[i].nd = h;
        }
      }
    }
    set<char> lets;
    RE(beg, SZ(s)) {
      lets.insert(s[beg - 1]);
      if (cnt.count(sufs[beg]) == 0) {
        continue;
      }
      auto &m = cnt[sufs[beg]];
      if (m.empty()) {
        continue;
      }
      for (auto let : lets) {
        res += m[let - 'a'];
      }
    }
  }

  cout << res - n << endl;

  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
#define MP make_pair
#define PB push_back
#define int long long
#define st first
#define nd second
#define rd third
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define RE(i, n) FOR(i, 1, n)
#define FORD(i, a, b) for (int i = (a); i >= (b); --i)
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define VAR(v, i) __typeof(i) v = (i)
#define FORE(i, c) for (VAR(i, (c).begin()); i != (c).end(); ++i)
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define __builtin_ctz __builtin_ctzll
#define __builtin_clz __builtin_clzll
#define __builtin_popcount __builtin_popcountll
using namespace std;
template <typename TH> void _dbg(const char *sdbg, TH h) {
  cerr << sdbg << "=" << h << "\\n";
}
template <typename TH, typename... TA>
void _dbg(const char *sdbg, TH h, TA... t) {
  while (*sdbg != ',') {
    cerr << *sdbg++;
  }
  cerr << "=" << h << ",";
  _dbg(sdbg + 1, t...);
}
#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#define debugv(x)                                                              \\
  {                                                                            \\
    {                                                                          \\
      cerr << #x << " = ";                                                     \\
      FORE(itt, (x)) cerr << *itt << ", ";                                     \\
      cerr << "\\n";                                                            \\
    }                                                                          \\
  }
#else
#define debug(...) (__VA_ARGS__)
#define debugv(x)
#define cerr                                                                   \\
  if (0)                                                                       \\
  cout
#endif
#define next ____next
#define prev ____prev
#define left ____left
#define hash ____hash
typedef long long ll;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VLL;
typedef vector<pair<int, int>> VPII;
typedef vector<pair<ll, ll>> VPLL;

template <class C> void mini(C &a4, C b4) { a4 = min(a4, b4); }
template <class C> void maxi(C &a4, C b4) { a4 = max(a4, b4); }
template <class T1, class T2>
ostream &operator<<(ostream &out, pair<T1, T2> pair) {
  return out << "(" << pair.first << ", " << pair.second << ")";
}
template <class A, class B, class C> struct Triple {
  A first;
  B second;
  C third;
  bool operator<(const Triple &t) const {
    if (st != t.st)
      return st < t.st;
    if (nd != t.nd)
      return nd < t.nd;
    return rd < t.rd;
  }
};
template <class T> void ResizeVec(T &, vector<int>) {}
template <class T> void ResizeVec(vector<T> &vec, vector<int> sz) {
  vec.resize(sz[0]);
  sz.erase(sz.begin());
  if (sz.empty()) {
    return;
  }
  for (T &v : vec) {
    ResizeVec(v, sz);
  }
}
typedef Triple<int, int, int> TIII;
template <class A, class B, class C>
ostream &operator<<(ostream &out, Triple<A, B, C> t) {
  return out << "(" << t.st << ", " << t.nd << ", " << t.rd << ")";
}
template <class T> ostream &operator<<(ostream &out, vector<T> vec) {
  out << "(";
  for (auto &v : vec)
    out << v << ", ";
  return out << ")";
}
template <class T> ostream &operator<<(ostream &out, set<T> vec) {
  out << "(";
  for (auto &v : vec)
    out << v << ", ";
  return out << ")";
}
template <class L, class R> ostream &operator<<(ostream &out, map<L, R> vec) {
  out << "(";
  for (auto &v : vec)
    out << v << ", ";
  return out << ")";
}

const int P[2] = {999999197, (int)1e9 + 7};
const int B[2] = {1234, 2345};

int32_t main() {

  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(10);
  cerr << fixed << setprecision(10);
  cin.tie(0);
  // double beg_clock = 1.0 * clock() / CLOCKS_PER_SEC;

  int n;
  cin >> n;
  map<PII, map<char, int>> cnt;
  vector<string> strs;
  RE(i, n) {
    string s;
    cin >> s;
    strs.PB(s);
    VI h(2);
    RE(j, SZ(s) - 1) {
      REP(tr, 2) { h[tr] = (h[tr] * B[tr] + s[j]) % P[tr]; }
    }
    cnt[{h[0], h[1]}][s[0]]++;
  }
  int res = 0;
  for (auto s : strs) {
    VPII sufs(SZ(s) + 1);
    REP(tr, 2) {
      int h = 0;
      int mul = 1;
      FORD(i, SZ(s) - 1, 1) {
        h = (h + mul * s[i]) % P[tr];
        mul = mul * B[tr] % P[tr];
        if (tr == 0) {
          sufs[i].st = h;
        } else {
          sufs[i].nd = h;
        }
      }
    }
    set<char> lets;
    RE(beg, SZ(s)) {
      lets.insert(s[beg - 1]);
      auto &m = cnt[sufs[beg]];
      for (auto let : lets) {
        res += m[let];
      }
    }
  }

  cout << res - n << endl;

  return 0;
}