链接：https://codeforces.com/gym/104090

A. Modulo Ruins the Legend

#include "bits/stdc++.h"

using namespace std;
using i64 = long long;

i64 exgcd(i64 a, i64 b, i64 &x, i64 &y) {
  if (!b) {
    x = 1;
    y = 0;
    return a;
  }
  i64 d = exgcd(b, a % b, x, y);
  i64 t = x;
  x = y;
  y = t - (a / b) * y;
  return d;
}

void solve() {
  i64 n, m;
  cin >> n >> m;
  vector<i64> A(n);
  for (int i = 0; i < n; i++) {
    cin >> A[i];
  }
  i64 sum = accumulate(A.begin(), A.end(), 0LL) % m;
  i64 m1 = n % m;
  i64 m2 = n * (n + 1) / 2 % m;
  i64 s = 0, d = 0, a = 0, b = 0;
  i64 m0 = exgcd(m1, m2, s, d);
  i64 m3 = exgcd(m0, m, a, b);
  s = s * a % m;
  d = d * a % m;
  i64 t = (m - sum + m3 - 1) / m3;
  cout << (t * m3 + sum) % m << '\n' << (s * t % m + m) % m << ' ' << (d * t % m + m) % m << '\n';
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int tt = 1;
  //cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}

D. Money Game

#include "bits/stdc++.h"

using namespace std;
using i64 = long long;

void solve() {
  int n;
  cin >> n;
  double sum = 0;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    sum += x;
  }
  double tmp = sum / (n + 1);
  cout << tmp * 2 << ' ';
  for (int i = 1; i < n; i++) {
    cout << tmp << ' ';
  }
  cout << '\n';
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  cout << fixed << setprecision(12);
  int tt = 1;
  //cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}

F. Da Mi Lao Shi Ai Kan De

#include "bits/stdc++.h"

using namespace std;
using i64 = long long;

void solve() {
  int n;
  cin >> n;
  set<string> mp;
  for (int i = 0; i < n; i++) {
    int k;
    cin >> k;
    bool ok = 0;
    for (int j = 0; j < k; j++) {
      string s;
      cin >> s;
      for (int p = 0; p + 2 < (int) s.size(); p++) {
        if (s[p] == 'b' && s[p + 1] == 'i' && s[p + 2] == 'e' && !mp.count(s)) {
          mp.insert(s);
          cout << s << '\n';
          ok = 1;
          break;
        }
      }
    }
    if (!ok) {
      cout << "Time to play Genshin Impact, Teacher Rice!" << '\n';
    }
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int tt = 1;
  //cin >> tt;
  for (int _ = 1; _ <= tt; _++) {
    solve();
  }
  return 0;
}

G. Subgraph Isomorphism

#include "bits/stdc++.h"

using namespace std;
using i64 = long long;

static constexpr int p[2] = {223333333, 773333333};
static constexpr int mod[2] = {1000000033, 1000002233};

using Hash = pair<i64, i64>;

#define x first
#define y second

void solve() {
  int n, m;
  cin >> n >> m;
  vector<vector<int>> g(n + 1);
  vector<int> deg(n + 1);
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
    deg[u]++;
    deg[v]++;
  }
  if (m == n - 1) {
    cout << "YES" << '\n';
    return;
  }
  if (m > n) {
    cout << "NO" << '\n';
    return;
  }
  queue<int> q;
  vector<bool> vis(n + 1);
  for (int i = 1; i <= n; i++) {
    if (deg[i] == 1) {
      q.push(i);
    }
  }
  int SIZE = n;
  while (!q.empty()) {
    int cur = q.front();
    q.pop();
    vis[cur] = 1;
    SIZE--;
    for (auto nex : g[cur]) {
      if (!vis[nex] && --deg[nex] == 1) {
        q.push(nex);
      }
    }
  }
  vector<i64> sz(n + 1);
  auto TreeHash = [&](int root) {
    function<Hash(int, int)> dfs = [&](int cur, int pre) {
      Hash res;
      sz[cur] = 1;
      vector<Hash> s;
      for (auto nex : g[cur]) {
        if (vis[nex] && nex != pre) {
          s.push_back(dfs(nex, cur));
          sz[cur] += sz[nex];
        }
      }
      sort(s.begin(), s.end(), greater<>());
      for (auto si : s) {
        res.x = (res.x * p[0] + si.x) % mod[0];
        res.y = (res.y * p[1] + si.y) % mod[1];
      }
      res.x = (res.x * p[0] + sz[cur]) % mod[0];
      res.y = (res.y * p[1] + sz[cur]) % mod[1];
      return res;
    };   
    return dfs(root, 0);
  };  
  vector<Hash> h;
  int pre = 0;
  int cur = 0;
  for (int i = 1; i <= n; i++) {
    if (!vis[i]) {
      cur = i;
      break;
    }
  }
  for (int i = 0; i < SIZE; i++) {
    h.push_back(TreeHash(cur));
    int now = 0;
    for (auto nex : g[cur]) {
      if (!vis[nex] && nex != pre) {
        now = nex;
        break;
      }
    }
    pre = cur;
    cur = now;
  }
  for (int i = 0; i < SIZE; i++) {
    if (h[i] != h[(i + 2) % SIZE]) {
      cout << "NO" << '\n';
      return;
    }
  }
  cout << "YES" << '\n';
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int tt = 1;
  cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}

K. Master of Both

#include "bits/stdc++.h"

using namespace std;
using i64 = long long;

constexpr int N = 26;

constexpr int M = 2E6;

i64 cnt[M + 10];
i64 add;
i64 num[N][N];
i64 ed[M + 10];

class Trie {
 public:
  int tot;
  vector<vector<int>> t;
  Trie(const int &n = 2E6) : t(n, vector<int>(N)), tot(0) {}
  inline void insert(const string &s) {
    int SIZE = s.size();
    int u = 0;
    for (int i = 0; i < SIZE; i++) {
      int c = s[i] - 'a';
      for (int j = 0; j < N; j++) {
        if (c != j && t[u][j]) {
          num[c][j] += cnt[t[u][j]];
        }
      }
      if (t[u][c] == 0) {
        t[u][c] = ++tot;
      }
      u = t[u][c];
      cnt[u]++;
    }
    ed[u]++;
    add += cnt[u] - ed[u];
  }
};

void solve() {
  int n, q;
  cin >> n >> q;
  Trie tree;
  for (int i = 0; i < n; i++) {
    string s;
    cin >> s;
    tree.insert(s);
  }
  for (int i = 0; i < q; i++) {
    string s;
    cin >> s;
    i64 ans = 0;
    for (int j = 0; j < N; j++) {
      for (int k = j; k < N; k++) {
        ans += num[s[j] - 'a'][s[k] - 'a'];
      }
    }
    cout << ans + add << '\n';
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int tt = 1;
  //cin >> tt;
  for (int _ = 1; _ <= tt; _++) {
    solve();
  }
  return 0;
}