Submission #1602387

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef vector<ll> vec;
typedef vector<vec> mat;

const ll INF = (1LL << 40) - 1;

mat mul(mat &A, mat &B) {
  mat C(A.size(), vec(B[0].size()));
  for (int i = 0; i < A.size(); i++) {
    for (int k = 0; k < B.size(); k++) {
      for (int j = 0; j < B[0].size(); j++) {
        C[i][j] ^= A[i][k] & B[k][j];
      }
    }
  }
  return C;
}

mat pow(mat A, int n) {
  mat B(A.size(), vec(A.size()));
  for (int i = 0; i < A.size(); i++) {
    B[i][i] = INF;
  }
  while (n > 0) {
    if (n & 1) B = mul(B, A);
    A = mul(A, A);
    n >>= 1;
  }
  return B;
}

int main(void) {
  int K, M;
  cin >> K >> M;

  vector<ll> a(K), c(K);
  for (int i = 0; i < K; i++) {
    cin >> a[i];
  }
  for (int i = 0; i < K; i++) {
    cin >> c[i];
  }

  mat A(K, vec(K));
  for (int i = 0; i < K; i++) {
    for (int j = 0; j < K; j++) {
      if (i == 0) {
        A[i][j] = c[j];
      } else if (j == i - 1) {
        A[i][j] = INF;
      }
    }
  }
  A = pow(A, M - K);

  ll ans = 0;
  if (M <= K) {
    ans = a[M - 1];
  } else {
    for (int i = 0; i < K; i++) {
      ans ^= A[0][i] & a[K - i - 1];
    }
  }

  cout << ans << endl;

  return 0;
}

Submission Info

Judge Result