Problem p02589 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<ll, ll>;
using Pld = pair<ld, ld>;
using Vec = vector<ll>;
using VecP = vector<P>;
using VecB = vector<bool>;
using VecC = vector<char>;
using VecD = vector<ld>;
using VecS = vector<string>;
using Graph = vector<VecP>;
template <typename T> using Vec1 = vector<T>;
template <typename T> using Vec2 = vector<Vec1<T>>;
#define REP(i, m, n) for (ll i = (m); i < (n); ++i)
#define REPN(i, m, n) for (ll i = (m); i <= (n); ++i)
#define REPR(i, m, n) for (ll i = (m)-1; i >= (n); --i)
#define REPNR(i, m, n) for (ll i = (m); i >= (n); --i)
#define rep(i, n) REP(i, 0, n)
#define repn(i, n) REPN(i, 1, n)
#define repr(i, n) REPR(i, n, 0)
#define repnr(i, n) REPNR(i, n, 1)
#define all(s) (s).begin(), (s).end()
#define pb push_back
#define fs first
#define sc second
template <typename T> bool chmax(T &a, const T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T> bool chmin(T &a, const T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T> ll pow2(const T n) { return (1LL << n); }
template <typename T> void cosp(const T n) { cout << n << ' '; }
void co(void) { cout << '\n'; }
template <typename T> void co(const T n) { cout << n << '\n'; }
template <typename T1, typename T2> void co(pair<T1, T2> p) {
  cout << p.fs << ' ' << p.sc << '\n';
}
template <typename T> void co(const Vec1<T> &v) {
  for (T i : v)
    cosp(i);
  co();
}
template <typename T> void co(initializer_list<T> v) {
  for (T i : v)
    cosp(i);
  co();
}
template <typename T> void ce(const T n) { cerr << n << endl; }
void sonic() {
  ios::sync_with_stdio(false);
  cin.tie(0);
}
void setp(const ll n) { cout << fixed << setprecision(n); }
constexpr int INF = 1e9 + 1;
constexpr ll LINF = 1e18 + 1;
constexpr ll MOD = 1e9 + 7;
// constexpr ll MOD = 998244353;
constexpr ld EPS = 1e-11;
const double PI = acos(-1);

struct Str {
  string s;
  char c;

  void input() {
    cin >> s;
    reverse(all(s));
    c = s.back();
    s.pop_back();
  }

  size_t size() { return s.size(); }
};

bool asc(Str &a, Str &b) {
  if (a.s == b.s)
    return a.c < b.c;
  return a.s < b.s;
}

int main(void) {
  ll n;
  cin >> n;
  vector<Str> s(n);
  rep(i, n) s[i].input();
  sort(all(s), asc);
  // rep(i, n) cout << s[i].s << "+" << s[i].c << endl;

  ll ans = 0;
  rep(i, n) {
    REP(j, i + 1, n) {
      if (s[i].size() >= s[j].size())
        continue;
      ll l = s[i].size();
      if (s[i].s == s[j].s.substr(0, l)) {
        if (s[j].s.find(s[i].c, l) != string::npos || s[i].c == s[j].c)
          ans++;
      } else
        break;
    }
  }
  co(ans);

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<ll, ll>;
using Pld = pair<ld, ld>;
using Vec = vector<ll>;
using VecP = vector<P>;
using VecB = vector<bool>;
using VecC = vector<char>;
using VecD = vector<ld>;
using VecS = vector<string>;
using Graph = vector<VecP>;
template <typename T> using Vec1 = vector<T>;
template <typename T> using Vec2 = vector<Vec1<T>>;
#define REP(i, m, n) for (ll i = (m); i < (n); ++i)
#define REPN(i, m, n) for (ll i = (m); i <= (n); ++i)
#define REPR(i, m, n) for (ll i = (m)-1; i >= (n); --i)
#define REPNR(i, m, n) for (ll i = (m); i >= (n); --i)
#define rep(i, n) REP(i, 0, n)
#define repn(i, n) REPN(i, 1, n)
#define repr(i, n) REPR(i, n, 0)
#define repnr(i, n) REPNR(i, n, 1)
#define all(s) (s).begin(), (s).end()
#define pb push_back
#define fs first
#define sc second
template <typename T> bool chmax(T &a, const T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T> bool chmin(T &a, const T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T> ll pow2(const T n) { return (1LL << n); }
template <typename T> void cosp(const T n) { cout << n << ' '; }
void co(void) { cout << '\n'; }
template <typename T> void co(const T n) { cout << n << '\n'; }
template <typename T1, typename T2> void co(pair<T1, T2> p) {
  cout << p.fs << ' ' << p.sc << '\n';
}
template <typename T> void co(const Vec1<T> &v) {
  for (T i : v)
    cosp(i);
  co();
}
template <typename T> void co(initializer_list<T> v) {
  for (T i : v)
    cosp(i);
  co();
}
template <typename T> void ce(const T n) { cerr << n << endl; }
void sonic() {
  ios::sync_with_stdio(false);
  cin.tie(0);
}
void setp(const ll n) { cout << fixed << setprecision(n); }
constexpr int INF = 1e9 + 1;
constexpr ll LINF = 1e18 + 1;
constexpr ll MOD = 1e9 + 7;
// constexpr ll MOD = 998244353;
constexpr ld EPS = 1e-11;
const double PI = acos(-1);

struct Str {
  string s;
  char c;

  void input() {
    cin >> s;
    reverse(all(s));
    c = s.back();
    s.pop_back();
  }

  size_t size() { return s.size(); }
};

bool asc(Str &a, Str &b) {
  if (a.s == b.s)
    return a.c < b.c;
  return a.s < b.s;
}

int main(void) {
  ll n;
  cin >> n;
  vector<Str> s(n);
  rep(i, n) s[i].input();
  sort(all(s), asc);
  // rep(i, n) cout << s[i].s << "+" << s[i].c << endl;

  ll ans = 0;
  rep(i, n) {
    REP(j, i + 1, n) {
      if (s[i].size() > s[j].size())
        break;
      if (s[i].size() == s[j].size())
        continue;
      ll l = s[i].size();
      if (s[i].s == s[j].s.substr(0, l)) {
        if (s[j].s.find(s[i].c, l) != string::npos || s[i].c == s[j].c)
          ans++;
      } else
        break;
    }
  }
  co(ans);

  return 0;
}