Submission #1092045

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092045		juicy	Money (IZhO17_money)	C++17	100 / 100	703 ms	66128 KiB

money

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

const int N = 1e6 + 5, inf = 1e9;

int n;
int a[N], nxt[N], f[N];

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

  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
  }
  for (int i = n; i >= 1; --i) {
    nxt[i] = a[i] <= a[i + 1] ? nxt[i + 1] : i;
  }
  set<int> st{0, inf};
  fill(f + 1, f + n + 1, inf);
  for (int i = 1; i <= n; ++i) {
    int x = *st.upper_bound(a[i]);
    int l = i + 1, r = nxt[i], p = i;
    while (l <= r) {
      int m = (l + r) / 2;
      if (a[m] <= x) {
        p = m;
        l = m + 1;
      } else {
        r = m - 1;
      }
    }
    st.insert(a[i]);
    f[p] = min(f[p], f[i - 1] + 1);
  }
  cout << f[n];
  return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55