Language: C++

#pragma region Macros
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define rep2(i, a, b) for(ll i = a; i <= b; ++i)
#define rep(i, n) for(ll i = 0; i < n; ++i)
#define rep3(i, a, b) for(ll i = a; i >= b; --i)
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define eb emplace_back
#define vi vector<int>
#define vll vector<ll>
#define vpi vector<pii>
#define vpll vector<pll>
#define overload2(_1, _2, name, ...) name
#define vec(type, name, ...) vector<type> name(__VA_ARGS__)
#define VEC(type, name, size)                                                                                                                                  \
    vector<type> name(size);                                                                                                                                   \
    IN(name)
#define vv(type, name, h, ...) vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define VV(type, name, h, w)                                                                                                                                   \
    vector<vector<type>> name(h, vector<type>(w));                                                                                                             \
    IN(name)
#define vvv(type, name, h, w, ...) vector<vector<vector<type>>> name(h, vector<vector<type>>(w, vector<type>(__VA_ARGS__)))
#define fi first
#define se second
#define all(c) begin(c), end(c)
#define ios ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define lb(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define ub(c, x) distance((c).begin(), upper_bound(all(c), (x)))
using namespace std;
template <class T> using pq = priority_queue<T>;
template <class T> using pqg = priority_queue<T, vector<T>, greater<T>>;
#define Size(c) (int)(c).size()
#define INT(...)                                                                                                                                               \
    int __VA_ARGS__;                                                                                                                                           \
    IN(__VA_ARGS__)
#define LL(...)                                                                                                                                                \
    ll __VA_ARGS__;                                                                                                                                            \
    IN(__VA_ARGS__)
#define ULL(...)                                                                                                                                               \
    ull __VA_ARGS__;                                                                                                                                           \
    IN(__VA_ARGS__)
#define STR(...)                                                                                                                                               \
    string __VA_ARGS__;                                                                                                                                        \
    IN(__VA_ARGS__)
#define CHR(...)                                                                                                                                               \
    char __VA_ARGS__;                                                                                                                                          \
    IN(__VA_ARGS__)
#define DBL(...)                                                                                                                                               \
    double __VA_ARGS__;                                                                                                                                        \
    IN(__VA_ARGS__)
#define LD(...)                                                                                                                                                \
    ld __VA_ARGS__;                                                                                                                                            \
    IN(__VA_ARGS__)
int scan() { return getchar(); }
template <class T> void scan(T a) { cin >> a; }
void scan(int &a) { cin >> a; }
void scan(long long &a) { cin >> a; }
void scan(char &a) { cin >> a; }
void scan(double &a) { cin >> a; }
void scan(long double &a) { cin >> a; }
void scan(char a[]) { scanf("%s", a); }
void scan(string &a) { cin >> a; }
template <class T> void scan(vector<T> &);
template <class T, size_t size> void scan(array<T, size> &);
template <class T, class L> void scan(pair<T, L> &);
template <class T, size_t size> void scan(T (&)[size]);
template <class T> void scan(vector<T> &a) {
    for(auto &i : a) scan(i);
}
template <class T> void scan(deque<T> &a) {
    for(auto &i : a) scan(i);
}
template <class T, size_t size> void scan(array<T, size> &a) {
    for(auto &i : a) scan(i);
}
template <class T, class L> void scan(pair<T, L> &p) {
    scan(p.first);
    scan(p.second);
}
template <class T, size_t size> void scan(T (&a)[size]) {
    for(auto &i : a) scan(i);
}
template <class T> void scan(T &a) { cin >> a; }
void IN() {}
template <class Head, class... Tail> void IN(Head &head, Tail &... tail) {
    scan(head);
    IN(tail...);
}
string stin() {
    string s;
    cin >> s;
    return s;
}
template <class T, class S> inline bool chmax(T &a, S b) {

    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T, class S> inline bool chmin(T &a, S b) {

    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}
vi iota(int n) {
    vi a(n);
    iota(all(a), 0);
    return a;
}
template <class T> void UNIQUE(vector<T> &x) {
    sort(all(x));
    x.erase(unique(all(x)), x.end());
}
int in() {
    int x;
    cin >> x;
    return x;
}
ll lin() {
    unsigned long long x;
    cin >> x;
    return x;
}
void print() { putchar(' '); }
void print(bool a) { cout << a; }
void print(int a) { cout << a; }
void print(long long a) { cout << a; }
void print(char a) { cout << a; }
void print(string &a) { cout << a; }
void print(double a) { cout << a; }
template <class T> void print(const vector<T> &);
template <class T, size_t size> void print(const array<T, size> &);
template <class T, class L> void print(const pair<T, L> &p);
template <class T, size_t size> void print(const T (&)[size]);
template <class T> void print(const vector<T> &a) {

    if(a.empty()) return;
    print(a[0]);
    for(auto i = a.begin(); ++i != a.end();) {
        cout << " ";
        print(*i);
    }
    cout << endl;
}
template <class T> void print(const deque<T> &a) {

    if(a.empty()) return;
    print(a[0]);
    for(auto i = a.begin(); ++i != a.end();) {
        cout << " ";
        print(*i);
    }
}
template <class T, size_t size> void print(const array<T, size> &a) {
    print(a[0]);
    for(auto i = a.begin(); ++i != a.end();) {
        cout << " ";
        print(*i);
    }
}
template <class T, class L> void print(const pair<T, L> &p) {
    cout << '(';
    print(p.first);
    cout << ",";
    print(p.second);
    cout << ')';
}
template <class T> void print(set<T> &x) {
    for(auto e : x) print(e), cout << " ";
    cout << endl;
}
template <class T> void print(multiset<T> &x) {
    for(auto e : x) print(e), cout << " ";
    cout << endl;
}
template <class T, size_t size> void print(const T (&a)[size]) {
    print(a[0]);
    for(auto i = a; ++i != end(a);) {
        cout << " ";
        print(*i);
    }
}
template <class T> void print(const T &a) { cout << a; }
int out() {
    putchar('\n');
    return 0;
}
template <class T> int out(const T &t) {
    print(t);
    putchar('\n');
    return 0;
}
template <class Head, class... Tail> int out(const Head &head, const Tail &... tail) {
    print(head);
    putchar(' ');
    out(tail...);
    return 0;
}
ll gcd(ll a, ll b) {
    while(b) {
        ll c = b;
        b = a % b;
        a = c;
    }
    return a;
}
ll lcm(ll a, ll b) {

    if(!a || !b) return 0;
    return a * b / gcd(a, b);
}
vector<pll> factor(ll x) {
    vector<pll> ans;
    for(ll i = 2; i * i <= x; i++)

        if(x % i == 0) {
            ans.push_back({i, 1});
            while((x /= i) % i == 0) ans.back().second++;
        }

    if(x != 1) ans.push_back({x, 1});
    return ans;
}
template <class T> vector<T> divisor(T x) {
    vector<T> ans;
    for(T i = 1; i * i <= x; i++)

        if(x % i == 0) {
            ans.pb(i);

            if(i * i != x) ans.pb(x / i);
        }
    return ans;
}
template <typename T> void zip(vector<T> &x) {
    vector<T> y = x;
    sort(all(y));
    for(int i = 0; i < x.size(); ++i) { x[i] = lb(y, x[i]); }
}
int popcount(ll x) { return __builtin_popcountll(x); }
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int n) { return uniform_int_distribution<int>(0, n - 1)(rng); }
ll rndll(ll n) { return uniform_int_distribution<ll>(0, n - 1)(rng); }
template <typename T> void shuffle(vector<T> &v) {
    rep3(i, v.size() - 1, 1) { swap(v[i], v[rnd(i)]); }
}
#define endl '\n'
vector<string> YES{"NO", "YES"};
vector<string> Yes{"No", "Yes"};
vector<string> yes{"no", "yes"};

#ifdef _LOCAL
#undef endl
#define debug(x)                                                                                                                                               \
    cout << #x << ": ";                                                                                                                                        \
    print(x);                                                                                                                                                  \
    cout << endl;
void err() {}
template <class T> void err(const T &t) {
    print(t);
    cout << " ";
}
template <class Head, class... Tail> void err(const Head &head, const Tail &... tail) {
    print(head);
    putchar(' ');
    out(tail...);
}
#else
#define debug(x)
template <class... T> void err(const T &...) {}
#endif

template <typename T> struct edge {
    int from, to;
    T cost;
    int id;
    edge(int to, T cost) : from(-1), to(to), cost(cost) {}
    edge(int from, int to, T cost) : from(from), to(to), cost(cost) {}
    edge(int from, int to, T cost, int id) : from(from), to(to), cost(cost), id(id) {}
    edge &operator=(const int &x) {
        to = x;
        return *this;
    }
    operator int() const { return to; }
};
template <typename T> using Edges = vector<edge<T>>;

struct Graph : vector<vector<int>> {
    using vector<vector<int>>::vector;
    Graph(int n, int m) : vector(n) { read(m); }
    inline void add(int a, int b, bool directed = false) {
        (*this)[a].emplace_back(b);

        if(!directed) (*this)[b].emplace_back(a);
    }
    void read(int n = -1, int offset = 1, bool directed = false) {

        if(n == -1) n = this->size() - 1;
        int a, b;
        while(n--) {
            cin >> a >> b;
            Graph::add(a - offset, b - offset, directed);
        }
    }
};
template <typename T> struct WeightedGraph : vector<Edges<T>> {
    using vector<Edges<T>>::vector;
    inline void add(int a, int b, T c, bool directed = false) {
        (*this)[a].emplace_back(b, c);

        if(!directed) (*this)[b].emplace_back(a, c);
    }
    void read(int n = -1, int offset = 1) {

        if(n == -1) n = this->size() - 1;
        int a, b;
        T c;
        while(n--) {
            cin >> a >> b >> c;
            WeightedGraph::add(a - offset, b - offset, c);
        }
    }
};
struct Setup_io {
    Setup_io() {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        cout << fixed << setprecision(15);
    }
} setup_io;

#define i128 __int128_t
#define ull unsigned long long int
#pragma endregion

// _________コーディングはここから！！___________
namespace RollingHashes {
static ull base;
struct RollingHash {
    static constexpr ull MOD = (1uL << 61) - 1;
    vector<u64> h, p;
    ull mul(ull a, ull b) const {
        i128 t = a;
        t *= b;
        t = (t >> 61) + (t & MOD);
        if(t >= MOD) return t - MOD;
        return t;
    }
    RollingHash(const string &s) {
        int sz = (int)s.size();
        if(!base) base = rnd(MOD);
        h.assign(sz + 1, 0), p.assign(sz + 1, 0);
        p[0] = 1;
        for(int i = 0; i < sz; i++) {
            h[i + 1] = mul(h[i], base), p[i + 1] = mul(p[i], base);
            if(h[i + 1] >= MOD) h[i + 1] -= MOD;
        }
    }

    ull get(int l, int r) const {
        ull res = h[r] + MOD - mul(h[l], p[r - l]);
        if(res >= MOD) return res - MOD;
        return res;
    }

    ull connect(ull h1, ull h2, int h2len) const {
        ull res = mul(h1, p1[h2len]) + h2;
        if(res >= MOD) return res - MOD;
        return res;
    }

    int LCP(const RollingHash &b, int l1, int r1, int l2, int r2) {
        int len = min(r1 - l1, r2 - l2);
        int low = -1, high = len + 1;
        while(high - low > 1) {
            int mid = (low + high) / 2;
            if(get(l1, l1 + mid) == b.get(l2, l2 + mid))
                low = mid;
            else
                high = mid;
        }
        return (low);
    }
    RollingHash() = default;
};

main() {
    INT(n);
    unordered_map<ll, int> mp;
    vector<string> s(n);
    rep(i, n) cin >> s[i], reverse(all(s[i]));
    sort(all(s), [&](string &l, string &r) { return size(l) < size(r); });
    ll ans = 0;
    rep(i, n) {
        RollingHash rh(s[i]);
        int mask = 0;
        rep3(j, size(s[i]) - 1, 0) {
            mask |= 1 << (s[i][j] - 'a');
            ans += popcount(mask & mp[rh.get(0, j)]);
        }
        mp[rh.get(0, size(s[i]) - 1)] += 1 << (s[i].back() - 'a');
    }
    cout << ans << endl;
}


Compiler output:
a.cc:349:12: error: 'u64' was not declared in this scope
  349 |     vector<u64> h, p;
      |            ^~~
a.cc:349:15: error: template argument 1 is invalid
  349 |     vector<u64> h, p;
      |               ^
a.cc:349:15: error: template argument 2 is invalid
a.cc: In constructor 'RollingHashes::RollingHash::RollingHash(const std::string&)':
a.cc:359:30: warning: overflow in conversion from 'long long unsigned int' to 'int' changes value from '2305843009213693951' to '-1' [-Woverflow]
  359 |         if(!base) base = rnd(MOD);
      |                              ^~~
a.cc:360:11: error: request for member 'assign' in '((RollingHashes::RollingHash*)this)->RollingHashes::RollingHash::h', which is of non-class type 'int'
  360 |         h.assign(sz + 1, 0), p.assign(sz + 1, 0);
      |           ^~~~~~
a.cc:360:32: error: request for member 'assign' in '((RollingHashes::RollingHash*)this)->RollingHashes::RollingHash::p', which is of non-class type 'int'
  360 |         h.assign(sz + 1, 0), p.assign(sz + 1, 0);
      |                                ^~~~~~
a.cc:361:10: error: invalid types 'int[int]' for array subscript
  361 |         p[0] = 1;
      |          ^
a.cc:363:14: error: invalid types 'int[int]' for array subscript
  363 |             h[i + 1] = mul(h[i], base), p[i + 1] = mul(p[i], base);
      |              ^
a.cc:363:29: error: invalid types 'int[int]' for array subscript
  363 |             h[i + 1] = mul(h[i], base), p[i + 1] = mul(p[i], base);
      |                             ^
a.cc:363:42: error: invalid types 'int[int]' for array subscript
  363 |             h[i + 1] = mul(h[i], base), p[i + 1] = mul(p[i], base);
      |                                          ^
a.cc:363:57: error: invalid types 'int[int]' for array subscript
  363 |             h[i + 1] = mul(h[i], base), p[i + 1] = mul(p[i], base);
      |                                                         ^
a.cc:364:17: error: invalid types 'int[int]' for array subscript
  364 |             if(h[i + 1] >= MOD) h[i + 1] -= MOD;
      |                 ^
a.cc:364:34: error: invalid types 'int[int]' for array subscript
  364 |             if(h[i + 1] >= MOD) h[i + 1] -= MOD;
      |                                  ^
a.cc: In member function 'long long unsigned int RollingHashes::RollingHash::get(int, int) const':
a.cc:369:20: error: invalid types 'const int[int]' for array subscript
  369 |         ull res = h[r] + MOD - mul(h[l], p[r - l]);
      |                    ^
a.cc:369:37: error: invalid types 'const int[int]' for array subscript
  369 |         ull res = h[r] + MOD - mul(h[l], p[r - l]);
      |                                     ^
a.cc:369:43: error: invalid types 'const int[int]' for array subscript
  369 |         ull res = h[r] + MOD - mul(h[l], p[r - l]);
      |                                           ^
a.cc: In member function 'long long unsigned int RollingHashes::RollingHash::connect(long long unsigned int, long long unsigned int, int) const':
a.cc:375:27: error: 'p1' was not declared in this scope; did you mean 'p'?
  375 |         ull res = mul(h1, p1[h2len]) + h2;
      |                           ^~
      |                           p
a.cc: At global scope:
a.cc:395:1: error: ISO C++ forbids declaration of 'main' with no type [-fpermissive]
  395 | main() {
      | ^~~~
a.cc: In function 'int RollingHashes::main()':
a.cc:412:1: warning: no return statement in function returning non-void [-Wreturn-type]
  412 | }
      | ^
a.cc: At global scope:
a.cc:412:2: error: expected '}' at end of input
  412 | }
      |  ^
a.cc:345:25: note: to match this '{'
  345 | namespace RollingHashes {
      |                         ^