Submission #932503

#	Time	Username	Problem	Language	Result	Execution time	Memory
932503		andrew	K blocks (IZhO14_blocks)	C++17	100 / 100	180 ms	83264 KiB

blocks

#include <bits/stdc++.h>


using namespace std;
typedef long long ll;


int main() {

    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k;
    cin >> n >> k;
    
    vector <ll> a(n);

    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }    

    vector <vector <ll>> dp(k + 1, vector <ll> (n, 1e15));

    dp[1][0] = a[0];
    ll mx = a[0];
    for (int i = 1; i < n; i++) {
        if (a[i] < mx) continue;
        dp[1][i] = a[i];
        mx = a[i];
    }

    for (int step = 2; step <= k; step++) {
        vector <ll> u(n, 1e15), f(n, 1e15);
        vector <int> st;
        for (int i = 0; i < n; i++) {
            while (!st.empty() && a[st.back()] < a[i]) {
                u[i] = min(u[i], u[st.back()]);
                u[i] = min(u[i], dp[step - 1][st.back()]);
                st.pop_back();
            }
            dp[step][i] = min(dp[step][i], u[i] + a[i]);
            f[i] = dp[step - 1][i];
            if (!st.empty()) {
                dp[step][i] = min(dp[step][i], f[st.back()] + a[i]);
                f[i] = min(f[i], f[st.back()]);
            }
            st.push_back(i);            
        }
    }   

    ll ans = dp[k][n - 1];
    mx = a[n - 1];
    for (int i = n - 2; i >= 0; i--) {
        if (mx > a[i]) continue;
        ans = min(ans, dp[k][i]);
        mx = a[i];
    }

    cout << ans << "\n";
    
    return 0;
}

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