Submission #671307

#	Time	Username	Problem	Language	Result	Execution time	Memory
671307		hct_2so1	K blocks (IZhO14_blocks)	C++14	0 / 100	1 ms	340 KiB

blocks

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
const int N = 1e5 + 5;
const ll INF = 1e18 + 7;
ll dp[N][3], n, k, a[N], st[4 * N];

void update(int id, int l, int r, int pos, ll val)
{
    if (l > r || pos < l || r < pos) return ;
    if (l == r)
    {
        st[id] = val;
        return ;
    }
    int mid = (l + r) / 2;
    if (pos <= mid) update(id * 2, l, mid, pos, val);
    else update(id * 2 + 1, mid + 1, r, pos, val);
    st[id] = min(st[id * 2], st[id * 2 + 1]);
}

int main()
{
    std::ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n>>k;
    for (int i = 1; i<=n; i++) cin>>a[i], dp[i][1] = max(dp[i - 1][1], a[i]);
    for (int i = 1; i<=4*n; i++) st[i] = INF;
    for (int j = 2; j<=k; j++)
    {
        stack<pair<int, ll>> s;
        int cur = j & 1;
        for (int i = j; i<=n; i++)
        {
            ll minF = dp[i - 1][1 - cur];
            while (s.size() && a[s.top().first] <= a[i])
                update(1, 1, n, s.top().first, INF), minF = min(minF, s.top().second), s.pop();
            dp[i][cur] = min(st[1], minF + a[i]);
            update(1, 1, n, i, dp[i][cur]);
            s.push({i, minF});
        }
    }
    cout<<dp[n][k & 1];
    return 0;
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 18
• Subtask 3: 0 / 21
• Subtask 4: 0 / 47