Submission #659159

#	Time	Username	Problem	Language	Result	Execution time	Memory
659159		600Mihnea	Martian DNA (BOI18_dna)	C++17	100 / 100	78 ms	14964 KiB

dna

#include <bits/stdc++.h>

using namespace std;

const int N = (int) 2e5 + 7;
const int INF = (int) 1e9 + 7;
int n;
int k;
int r;
int d[N];
vector<int> positions[N];
int min_quantity[N];
int rgh[N];

void upd(int l, int r) {
  rgh[l] = max(rgh[l], r);
}

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

//  freopen ("input.txt", "r", stdin);


  cin >> n >> k >> r;
  for (int i = 0; i < n; i++) {
    cin >> d[i];
    positions[d[i]].push_back(i);
  }
  for (int i = 0; i < r; i++) {
    int base, quantity;
    cin >> base >> quantity;
    min_quantity[base] = max(min_quantity[base], quantity);
  }

  for (int i = 0; i < n; i++) {
    rgh[i] = i;
  }

  for (int base = 0; base < k; base++) {
    if (min_quantity[base] == 0) {
      continue;
    }
    int sz = (int) positions[base].size();
    int need = min_quantity[base];
    if (sz < need) {
      upd(0, n);
      continue;
    }
    /// sz >= min_quantity[base]
    upd(0, positions[base][need - 1]);
    for (int i = 0; i < sz; i++) {
      if (i + need < sz) {
        upd(positions[base][i] + 1, positions[base][i + need]);
      } else {
        upd(positions[base][i] + 1, n);
      }
    }
  }

  for (int l = 0; l < n; l++) {
    rgh[l + 1] = max(rgh[l + 1], rgh[l]);
  }

  int best_dif = INF;

  for (int l = 0; l < n; l++) {
    if (rgh[l] != n) {
      best_dif = min(best_dif, rgh[l] - l + 1);
    }
  }
  if (best_dif == INF) {
    cout << "impossible\n";
    return 0;
  }
  cout << best_dif << "\n";

  return 0;
}

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