https://www.luogu.com.cn/problem/P3370

#include <bits/stdc++.h>
using namespace std;
const int base1 = 29, base2 = 131, M = 2e5 + 5, mod1 = 1e9 + 7, mod2 = 1e9 + 9;
int hash1[M], hash2[M], pow1[M], pow2[M];
string s;
struct Hash
{
public:
    void init(string s)
    {
        // 下标从1开始
        hash1[0] = hash2[0] = 0;
        pow1[0] = pow2[0] = 1;
        int n = s.size();
        for (int i = 1; i <= n; ++i)
        {
            pow1[i] = pow1[i - 1] * base1 % mod1;
            pow2[i] = pow2[i - 1] * base2 % mod2;
        }
        for (int i = 1; i <= n; ++i)
        {
            hash1[i] = (hash1[i - 1] * base1 + s[i]) % mod1;
            hash2[i] = (hash2[i - 1] * base2 + s[i]) % mod2;
        }
    }
    pair<int, int> gethash(string s, int l, int r)
    {
        return {(hash1[r] - hash1[l - 1] * pow1[r - l + 1] % mod1 + mod1) % mod1, (hash2[r] - hash2[l - 1] * pow2[r - l + 1] % mod2 + mod2) % mod2};
    }
};
int main()
{
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    int t;
    cin >> t;
    set<pair<int, int>> f;
    while (t--)
    {
        cin >> s;
        s = " " + s;
        int n = s.size();
        Hash h;
        h.init(s);
        f.insert(h.gethash(s, 1, n - 1));
    }
    cout << f.size();
    return 0;
}