Submission #403984

#	Time	Username	Problem	Language	Result	Execution time	Memory
403984		rama_pang	Martian DNA (BOI18_dna)	C++17	100 / 100	43 ms	4540 KiB

dna

#include <bits/stdc++.h>
using namespace std;

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int N, K, R;
  cin >> N >> K >> R;

  vector<int> A(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i];
  }

  vector<int> B(K);
  for (int i = 0; i < R; i++) {
    int x, y;
    cin >> x >> y;
    B[x] = y;
  }

  int ans = N + 1;

  int bad = R;
  vector<int> freq(K);
  const auto Modify = [&](int k, int sgn) {
    bad -= freq[k] < B[k];
    freq[k] += sgn;
    bad += freq[k] < B[k];
  };

  for (int i = 0, j = 0; i < N; i++) {
    Modify(A[i], +1);
    while (bad == 0) {
      Modify(A[j], -1);
      if (bad == 0) {
        j += 1;
      } else {
        Modify(A[j], +1);
        break;
      }
    }
    if (bad == 0) {
      ans = min(ans, i - j + 1);
    }
  }

  if (ans > N) {
    cout << "impossible\n";
  } else {
    cout << ans << '\n';
  }
  return 0;
}

• Subtask 1: 16 / 16
• Subtask 2: 24 / 24
• Subtask 3: 28 / 28
• Subtask 4: 32 / 32