Submission #1233513

#	Time	Username	Problem	Language	Result	Execution time	Memory
1233513		mannshah1211	K blocks (IZhO14_blocks)	C++20	100 / 100	130 ms	3912 KiB

blocks

/**
 *    author: tourist
 *    created: 02.07.2025 17:15:02
**/
#include <bits/stdc++.h>

using namespace std;

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

const long long inf = (long long) 1e18;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, k;
  cin >> n >> k;
  vector<long long> a(n + 1);
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  vector<long long> dp(n + 1, inf), ndp(n + 1, inf);
  for (int i = 1; i <= n; i++) {
    if (i == 1) {
      dp[i] = a[i];
      continue;
    }
    dp[i] = max(dp[i - 1], a[i]);
  }
  vector<int> l(n + 1, 0);
  stack<int> lef;
  for (int i = 1; i <= n; i++) {
    while (!lef.empty() && a[lef.top()] <= a[i]) {
      lef.pop();
    }
    if (!lef.empty()) {
      l[i] = lef.top();
    }
    lef.push(i);
  }
  for (int i = 2; i <= k; i++) {
    stack<pair<long long, long long>> st;
    for (int j = 1; j <= n; j++) {
      if (l[j] != 0) {
        ndp[j] = ndp[l[j]];
      }
      long long mn = dp[j - 1];
      while (!st.empty() && st.top().second <= a[j]) {
        mn = min(mn, st.top().first);
        st.pop();
      }
      ndp[j] = min(ndp[j], mn + a[j]);
      st.push({mn, a[j]});
    }
    for (int j = 0; j <= n; j++) {
      dp[j] = ndp[j];
      ndp[j] = inf;
    }
  }
  cout << dp[n] << '\n';
  return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 47 / 47