Submission #579198

#	Time	Username	Problem	Language	Result	Execution time	Memory
579198		tengiz05	Cubeword (CEOI19_cubeword)	C++17	0 / 100	831 ms	4932 KiB

cubeword

#include <bits/stdc++.h>

using namespace std;

const string ex = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

constexpr int P = 998244353;
using i64 = long long;

constexpr int K = 55;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int n;
    cin >> n;
    
    vector<vector<string>> s(11);
    for (int i = 0; i < n; i++) {
        string g;
        cin >> g;
        string t(g.rbegin(), g.rend());
        if (t < g)
            g = t;
        s[g.size()].push_back(g);
    }
    
    auto work = [&](vector<string> &s) {
        sort(s.begin(), s.end());
        s.erase(unique(s.begin(), s.end()), s.end());
        
        int n = s.size();
        int cnt[K][K] {}, cntp[K][K] {};
        for (int i = 0; i < n; i++) {
            int x = ex.find(s[i][0]);
            int y = ex.find(s[i].back());
            string t(s[i].rbegin(), s[i].rend());
            if (s[i] == t) {
                cntp[x][y] += 1;
            } else {
                cnt[x][y] += 1;
                cnt[y][x] += 1;
            }
        }
        
        i64 dp[K][K][K] {};
        
        for (int a = 0; a < K; a++) {
            for (int b = 0; b < K; b++) {
                for (int c = 0; c < K; c++) {
                    for (int x = 0; x < K; x++) {
                        i64 res = ((a == x) * cntp[a][x]) + cnt[a][x];
                        res = res * (((b == x) * cntp[b][x]) + cnt[b][x]) % P;
                        res = res * (((c == x) * cntp[c][x]) + cnt[c][x]) % P;
                        dp[a][b][c] += res;
                        if (dp[a][b][c] >= P)
                            dp[a][b][c] -= P;
                    }
                }
            }
        }
        
        i64 ans = 0;
        
        for (int a = 0; a < K; a++) {
            for (int b = 0; b < K; b++) {
                for (int c = 0; c < K; c++) {
                    for (int d = 0; d < K; d++) {
                        ans += ((dp[a][b][c] * dp[a][c][d]) % P * (dp[a][b][d] * dp[b][c][d]) % P) % P;
                        if (ans >= P)
                            ans -= P;
                    }
                }
            }
        }
        
        return ans;
    };
    
    i64 ans = 0;
    for (int k = 3; k <= 10; k++) {
        ans += work(s[k]);
        if (ans >= P)
            ans -= P;
    }
    
    cout << ans << "\n";
    
    return 0;
}

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