Submission #1276612

#	Time	Username	Problem	Language	Result	Execution time	Memory
1276612		MisterReaper	Cubeword (CEOI19_cubeword)	C++20	0 / 100	102 ms	15588 KiB

cubeword

// File cubeword.cpp created on 06.10.2025 at 09:23:37
#include <bits/stdc++.h>

using i64 = long long;

#ifdef DEBUG 
    #include "/home/ahmetalp/Desktop/Workplace/debug.h"
#else
    #define debug(...) void(23)
#endif

template<typename T>
T power(T a, i64 b) {
    T res {1};
    while (b) {
        if (b & 1) {
            res *= a;
        }
        a *= a;
        b >>= 1;
    }
    return res;
}

constexpr int md = 998244353;
struct MInt {
    int val;
    MInt() : val(0) {}
    template<typename T>
    MInt(T x) {
        if (-md <= x && x < md) {
            val = x;
        } else {
            val = x % md;
        }
    }
    int operator()() { return val; }
    MInt& operator+= (MInt rhs) {
        if ((val += rhs.val) >= md) {
            val -= md;
        }
        return *this;
    }
    MInt& operator-= (MInt rhs) {
        if ((val -= rhs.val) < 0) {
            val += md;
        }
        return *this;
    }
    MInt& operator*= (MInt rhs) {
        val = int(1LL * val * rhs.val % md);
        return *this;
    }
    MInt inv() {
        return power(*this, md - 2);
    }
    MInt& operator/= (MInt rhs) {
        return *this *= rhs.inv();
    }
};
MInt operator+ (MInt lhs, MInt rhs) {
    return lhs += rhs;
}
MInt operator- (MInt lhs, MInt rhs) {
    return lhs -= rhs;
}
MInt operator* (MInt lhs, MInt rhs) {
    return lhs *= rhs;
}
MInt operator/ (MInt lhs, MInt rhs) {
    return lhs /= rhs;
}

using Z = MInt;

int alp[256];
constexpr int SZ = 6;
constexpr int BASE = 67;

i64 hash(std::vector<int> v) {
    i64 h = 0;
    for (auto i : v) {
        h = h * BASE + i;
    }
    return h;
}

Z solve(int n, std::vector<std::vector<int>>& vec) {
    debug(n, vec);
    if (vec.empty()) {
        return 0;
    }
    std::set<i64> vis;
    std::array<std::array<int, SZ + 1>, SZ + 1> cnt {};
    for (auto s : vec) {
        for (int _ = 0; _ < 2; ++_) {
            i64 h = hash(s);
            if (!vis.count(h)) {
                cnt[s[0]][s[n - 1]] += 1;
                vis.emplace(h);
            }
            std::reverse(s.begin(), s.end());
        }
    }

    Z ans = 0;
    for (int a = 1; a <= SZ; ++a) {
        for (int b = 1; b <= SZ; ++b) {
            for (int c = 1; c <= SZ; ++c) {
                for (int d = 1; d <= SZ; ++d) {
                    for (int e = 1; e <= SZ; ++e) {
                        for (int f = 1; f <= SZ; ++f) {
                            for (int g = 1; g <= SZ; ++g) {
                                for (int h = 1; h <= SZ; ++h) {
                                    ans += 1LL * cnt[a][b] * cnt[a][e] * cnt[a][c] * cnt[b][d] * cnt[b][g] * cnt[c][d] * cnt[c][f] * cnt[d][h] * cnt[e][g] * cnt[e][f] * cnt[f][h] * cnt[g][h];
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    return ans;
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int cnt = 1;
    for (char c = 'a'; c <= 'z'; ++c) {
        alp[c] = cnt++;
    }
    for (char c = 'A'; c <= 'Z'; ++c) {
        alp[c] = cnt++;
    }
    for (char c = '0'; c <= '9'; ++c) {
        alp[c] = cnt++;
    }

    int N;
    std::cin >> N;

    std::vector<std::vector<int>> A(N);
    for (int i = 0; i < N; ++i) {
        std::string S;
        std::cin >> S;
        int n = int(S.size());
        A[i].resize(n);
        for (int j = 0; j < n; ++j) {
            A[i][j] = alp[S[j]];
        }
    }

    constexpr int MAX = 10;

    std::vector<std::vector<std::vector<int>>> vec(MAX + 1);
    for (int i = 0; i < N; ++i) {
        vec[A[i].size()].emplace_back(A[i]);
    }

    Z ans = 0;
    for (int i = 3; i <= MAX; ++i) {
        Z x = solve(i, vec[i]);
        ans += x;
    }

    std::cout << ans.val << '\n';

    return 0;
}

• Subtask 1: 0 / 21
• Subtask 2: 0 / 29
• Subtask 3: 0 / 34
• Subtask 4: 0 / 16