Submission #425595

#	Time	Username	Problem	Language	Result	Execution time	Memory
425595		MilosMilutinovic	Exam (eJOI20_exam)	C++14	12 / 100	1088 ms	1112 KiB

exam

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

typedef long long ll;
typedef long unsigned long ull;
typedef double long ld;

int n, a[100050], b[100050];

void solve2() {
  for (int i = 1; i <= n; i++) {
    if (a[i] == b[i]) {
      for (int j = i + 1; j <= n; j++) {
        if (a[j] >= a[i]) {
          break;
        }
        a[j] = a[i];
      }
      for (int j = i - 1; j >= 1; j--) {
        if (a[j] >= a[i]) {
          break;
        }
        a[j] = a[i];
      }
    }
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    ans += (a[i] == b[i] ? 1 : 0);
  }
  cout << ans << '\n';
}

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

  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i <= n; i++) {
    cin >> b[i];
  }
  if (*max_element(b + 1, b + n + 1) == *min_element(b + 1, b + n + 1)) {
    solve2();
    return 0;
  }
  bool sub3 = true;
  for (int i = 2; i <= n; i++) {
    if (a[i] <= a[i - 1]) {
      sub3 = false;
    }
  }
  if (sub3) {
    map<int, int> mp;
    for (int i = 1; i <= n; i++) {
      mp[a[i]] = i;
    }
    for (int i = 1; i <= n; i++) {
      b[i] = mp[b[i]];
    }
    vector<int> dp(n + 1);
    for (int i = 1; i <= n; i++) {
      dp[i] = 1;
      for (int j = 1; j < i; j++) {
        if (b[j] > 0 && b[i] >= b[j]) {
          dp[i] = max(dp[i], dp[j] + 1);
        }
      }
    }
    cout << *max_element(dp.begin(), dp.end()) << '\n';
    return 0;
  }
  if (n <= 10) {
    auto c = a;
    int ans = 0;
    function<void(int*)> Brut = [&](int* niz) {
      int cnt = 0;
      for (int i = 1; i <= n; i++) {
        cnt += niz[i] == b[i];
      }
      ans = max(ans, cnt);
      for (int i = 1; i <= n; i++) {
        int mx = 0;
        int novi[n + 1];
        for (int j = 1; j <= n; j++) {
          novi[j] = niz[j];
        }
        for (int j = i; j <= n; j++) {
          mx = max(mx, niz[j]);
          bool ok = false;
          for (int l = i; l <= j; l++) {
            if (niz[l] != mx) {
              ok = true;
            }
            novi[l] = mx;
          }
          if (ok) {
            Brut(novi);
          }
        }
      }
    };
    Brut(c);
    cout << ans << '\n';
  }
}

• Subtask 1: 0 / 14
• Subtask 2: 12 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22