Submission #1277165

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277165		MisterReaper	Cubeword (CEOI19_cubeword)	C++20	100 / 100	137 ms	17896 KiB

cubeword

// File cubeword.cpp created on 08.10.2025 at 10:41:52 08
#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;
        }
        if (val < 0) {
            val += 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();
    }
    bool operator== (MInt rhs) {
        return val == rhs.val;
    }
    bool operator!= (MInt rhs) {
        return val != rhs.val;
    }
};
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;

constexpr int SZ = 62;

i64 hash(std::vector<int>& vec) {
    i64 x = 0;
    for (auto i : vec) {
        x = x * (SZ + 1) + (i + 1);
    }
    return x;
}

Z solve(int n, std::vector<std::vector<int>> vecs) {
    debug(1);
    Z cnt[SZ][SZ];
    std::set<i64> vis;
    for (auto v : vecs) {
        for (int _ = 0; _ < 2; ++_) {
            i64 h = hash(v);
            if (!vis.count(h)) {
                vis.emplace(h);
                cnt[v[0]][v[n - 1]] += 1;
            }
            std::reverse(v.begin(), v.end());
        }
    }
    Z f[SZ][SZ][SZ];
    for (int a = 0; a < SZ; ++a) {
        for (int b = 0; b < SZ; ++b) {
            for (int c = b; c < SZ; ++c) {
                for (int d = c; d < SZ; ++d) {
                    f[b][c][d] += cnt[a][b] * cnt[a][c] * cnt[a][d];
                }
            }
        }
    }
    Z ans = 0;
    for (int a = 0; a < SZ; ++a) {
        for (int b = a; b < SZ; ++b) {
            for (int c = b; c < SZ; ++c) {
                for (int d = c; d < SZ; ++d) {
                    Z x = f[a][b][c] * f[a][b][d] * f[a][c][d] * f[b][c][d];
                    int p;
                    if (a == d) {
                        p = 1;
                    } else if (a == c) {
                        p = 4;
                    } else if (a == b) {
                        if (c == d) {
                            p = 6;
                        } else {
                            p = 12;
                        }
                    } else {
                        if (b == d) {
                            p = 4;
                        } else if (b == c) {
                            p = 12;
                        } else {
                            if (c == d) {
                                p = 12;
                            } else {
                                 p = 24;
                            }
                        }
                    }
                    ans += x * p;
                }
            }
        }
    }
    return ans;
}

int alp[256];

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

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

    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]];
        }
    }

    std::vector<std::vector<std::vector<int>>> groups(11);
    for (int i = 0; i < N; ++i) {
        groups[A[i].size()].push_back(A[i]);
    }

    Z ans = 0;
    for (int i = 3; i <= 10; ++i) {
        debug(i, groups[i]);
        ans += solve(i, groups[i]);
    }

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

    return 0;
}

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