Submission #226305

#	Time	Username	Problem	Language	Result	Execution time	Memory
226305		emil_physmath	K blocks (IZhO14_blocks)	C++17	0 / 100	25 ms	21120 KiB

blocks

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
inline int pow2(int i) { return 1 << i; }
const int maxN = 100'000;
const int lg = 16;
struct Sparse
{
    int t[lg + 1][maxN];
    Sparse()
    {
        for (int i = 0; i <= lg; ++i)
            for (int j = 0; j < 20; ++j)
                t[i][j] = 1000'000 * 100 + 1;
    }
    void set(int i, int val)
    {
        t[0][i] = val;
        for (int j = 1; j <= lg && pow2(j) <= i + 1; ++j)
            t[j][i] = min(t[j - 1][i], t[j - 1][i - pow2(j - 1)]);
    }
    int operator()(int l, int r)
    {
        int i = __lg(r - l + 1);
        return min(t[i][r], t[i][l + pow2(i) - 1]);
    }
};

Sparse dp[101];

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, k;
    cin >> n >> k;
    vector<int> a(n);
    for (int i = 0; i < n; ++i)
        cin >> a[i];
    dp[1].set(0, a[0]);
    for (int i = 1; i < n; ++i)
        dp[1].set(i, max(dp[1](i - 1, i - 1), a[i]));
    vector<int> st;
    for (int i = 1; i < n; ++i)
    {
        auto it = upper_bound(st.rbegin(), st.rend(), i, [&a](int i, int j){ return a[i] < a[j]; });
        int m = (it == st.rend() ? -1 : *it);
        for (int j = 2; j <= k; ++j)
        {
            int cur = 1000'000 * k + 1;
            if (m != -1)
                cur = min(cur, dp[j](m, m));
            if (m + 1 < i)
                cur = min(cur, dp[j - 1](m + 1, i - 1) + a[i]);
            dp[j].set(i, cur);
        }
        while (st.size() && a[st.back()] <= a[i])
            st.pop_back();
        st.push_back(i);
    }
    cout << dp[k](n - 1, n - 1);
}

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