Cod sursa(job #2432574)

Utilizator AlexPop28Pop Alex-Nicolae AlexPop28 Data 24 iunie 2019 13:17:32
Problema Pod Scor 75
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.64 kb
#include <bits/stdc++.h>
#define DEBUG(x) cerr << (#x) << ": " << (x) << '\n'

using namespace std;

const int MOD = 9901;

struct Matrix {
  int n;
  int a[20][20];
  Matrix(int n) : n(n) {
    memset(a, 0, sizeof(a));
  }
  int* operator[](const int pos) {
    return a[pos];
  }
  Matrix operator*(Matrix &b) const {
    Matrix res(n);
    for (int i = 0; i < n; ++i) {
      for (int k = 0; k < n; ++k) {
        for (int j = 0; j < n; ++j) {
          res[i][j] += a[i][k] * b[k][j] % MOD;
          if (res[i][j] >= MOD) res[i][j] -= MOD;
        }
      }
    }
    return res;
  }
  Matrix toPow(int e) {
    Matrix res = *this, b = *this;
    --e;
    while (e) {
      if (e & 1)
        res = res * b;
      b = b * b;
      e >>= 1;
    }
    return res;
  }
};

int main() {
  freopen("pod.in", "r", stdin);
  freopen("pod.out", "w", stdout);
  ios::sync_with_stdio(0);
  cin.tie(0);

  int n, m, k; scanf("%d%d%d", &n, &m, &k);
  vector<int> v(m);
  for (int i = 0; i < m; ++i) {
    scanf("%d", &v[i]);
  }
  sort(v.begin(), v.end()); // ffs
  v.erase(unique(v.begin(), v.end()), v.end());
  Matrix tr(k);
  for (int i = 0; i < k - 1; ++i) {
    tr[i][i + 1] = 1;
  }
  tr[k - 1][0] = tr[k - 1][k - 1] = 1;
  
  Matrix dp(k);
  dp[k - 1][0] = 1; // dp = {{dp[-i],.., 0},..., {dp[0], 0}}
  
  int last = 0;
  for (int i = 0; i < m; ++i) {
    int e = v[i] - last;
    dp = move(tr.toPow(e) * dp);
    dp[k - 1][0] = 0; // dp[v[i]] = 0
    last = v[i];
  }
  dp = move(tr.toPow(n - last) * dp);
  cout << dp[k - 1][0] << endl;

#ifdef LOCAL_DEFINE
  cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif
  return 0;
}