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

#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define R cin >>
#define ll long long
#define ln cout << '\\n'
#define in(a) insert(a)
#define pb(a) push_back(a)
#define pd(a) printf("%.10f\\n", a)
#define mem(a) memset(a, 0, sizeof(a))
#define all(c) (c).begin(), (c).end()
#define iter(c) __typeof((c).begin())
#define rrep(i, n) for (ll i = (ll)(n)-1; i >= 0; i--)
#define REP(i, m, n) for (ll i = (ll)(m); i < (ll)(n); i++)
#define rep(i, n) REP(i, 0, n)
#define tr(it, c) for (iter(c) it = (c).begin(); it != (c).end(); it++)
ll check(ll n, ll m, ll x, ll y) { return x >= 0 && x < n && y >= 0 && y < m; }
void pr() { ln; }
template <class A, class... B> void pr(const A &a, const B &...b) {
  cout << a << (sizeof...(b) ? " " : "");
  pr(b...);
}
template <class A> void PR(A a, ll n) {
  rep(i, n) cout << (i ? " " : "") << a[i];
  ln;
}
const ll MAX = 1e9 + 7, MAXL = 1LL << 61, dx[8] = {-1, 0, 1, 0, -1, -1, 1, 1},
         dy[8] = {0, 1, 0, -1, -1, 1, 1, -1};
typedef pair<ll, string> P;
typedef pair<unsigned long long, int> PP;

struct RH {
  vector<unsigned long long> p, hash;
  void init(const string s) {
    unsigned long long m = 1000000007, q = 1, n = s.size();
    p.resize(n + 1);
    hash.resize(n + 1);
    p[0] = q;
    hash[0] = 0;
    rep(i, n) {
      p[i + 1] = p[i] * m;
      hash[i + 1] = s[i] + hash[i] * m;
    }
  }
  unsigned long long h(int i) const { return hash[i]; }
  unsigned long long h(int i, int j) const { return h(j) - h(i) * p[j - i]; }
};

map<PP, int> m[1000001];

RH r;
P p[200002];
void Main() {
  ll n;
  R n;
  rep(i, n) {
    R p[i].S;
    p[i].F = p[i].S.size();
    reverse(all(p[i].S));
  }
  sort(p, p + n);
  ll ans = 0;
  rep(l, n) {
    string t = p[l].S;
    r.init(t);
    ll c[26];
    mem(c);
    ll mm = t.size();
    rrep(i, mm) {
      int k = t[i] - 'a';
      c[k] = 1;
      rep(j, 26) {
        if (c[j] && m[i].count(PP(r.h(i), j)))
          ans += m[i][PP(r.h(i), j)];
      }
    }
    int k = t[mm - 1] - 'a';
    m[mm - 1][PP(r.h(mm - 1), k)]++;
  }
  pr(ans);
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  Main();
  return 0;
}


Error: MLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define R cin >>
#define ll long long
#define ln cout << '\\n'
#define in(a) insert(a)
#define pb(a) push_back(a)
#define pd(a) printf("%.10f\\n", a)
#define mem(a) memset(a, 0, sizeof(a))
#define all(c) (c).begin(), (c).end()
#define iter(c) __typeof((c).begin())
#define rrep(i, n) for (ll i = (ll)(n)-1; i >= 0; i--)
#define REP(i, m, n) for (ll i = (ll)(m); i < (ll)(n); i++)
#define rep(i, n) REP(i, 0, n)
#define tr(it, c) for (iter(c) it = (c).begin(); it != (c).end(); it++)
ll check(ll n, ll m, ll x, ll y) { return x >= 0 && x < n && y >= 0 && y < m; }
void pr() { ln; }
template <class A, class... B> void pr(const A &a, const B &...b) {
  cout << a << (sizeof...(b) ? " " : "");
  pr(b...);
}
template <class A> void PR(A a, ll n) {
  rep(i, n) cout << (i ? " " : "") << a[i];
  ln;
}
const ll MAX = 1e9 + 7, MAXL = 1LL << 61, dx[8] = {-1, 0, 1, 0, -1, -1, 1, 1},
         dy[8] = {0, 1, 0, -1, -1, 1, 1, -1};
typedef pair<ll, string> P;

struct RH {
  vector<unsigned long long> p, hash;
  void init(const string s) {
    unsigned long long m = 1000000007, q = 1, n = s.size();
    p.resize(n + 1);
    hash.resize(n + 1);
    p[0] = q;
    hash[0] = 0;
    rep(i, n) {
      p[i + 1] = p[i] * m;
      hash[i + 1] = s[i] + hash[i] * m;
    }
  }
  unsigned long long h(int i) const { return hash[i]; }
  unsigned long long h(int i, int j) const { return h(j) - h(i) * p[j - i]; }
};

map<unsigned long long, int> m[1000001][26];

RH r;
P p[200002];
void Main() {
  ll n;
  R n;
  rep(i, n) {
    R p[i].S;
    p[i].F = p[i].S.size();
    reverse(all(p[i].S));
  }
  sort(p, p + n);
  ll ans = 0;
  rep(l, n) {
    string t = p[l].S;
    r.init(t);
    ll c[26];
    mem(c);
    ll mm = t.size();
    rrep(i, mm) {
      int k = t[i] - 'a';
      c[k] = 1;
      rep(j, 26) {
        if (c[j] && m[i][j].count(r.h(i)))
          ans += m[i][j][r.h(i)];
      }
    }
    int k = t[mm - 1] - 'a';
    m[mm - 1][k][r.h(mm - 1)]++;
  }
  pr(ans);
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  Main();
  return 0;
}