Submission #891129

#	Time	Username	Problem	Language	Result	Execution time	Memory
891129		The_Samurai	K blocks (IZhO14_blocks)	C++17	53 / 100	1016 ms	4180 KiB

blocks

//#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2")

#include "bits/stdc++.h"

using namespace std;
using ll = long long;
const int inf = 1e9;

template<typename T> struct SegTree {
    vector<T> tree;
    int size;
    T neutral_element = 1e9; // sum - 0, mx - (-INF), mn - INF

    inline T merge(T a, T b) {
        return min(a, b);
    }

    void init(int n) {
        size = 1;
        while (size <= n) size *= 2;
        tree.assign(2 * size, neutral_element);
    }

    void build(vector<T> &a) {
        size = 1;
        while (size < a.size()) size *= 2;
        tree.assign(2 * size, neutral_element);
        for (int i = size; i < size + a.size(); i++) tree[i] = a[i - size];
        for (int i = size - 1; i > 0; i--) tree[i] = merge(tree[i << 1], tree[i << 1 | 1]);
    }

    void set(int p, T value, bool add) {  // set value at position p
        p += size;
        tree[p] = merge(add ? tree[p] : neutral_element, value);
        for (; p > 1; p >>= 1) tree[p >> 1] = merge(tree[p], tree[p ^ 1]);
    }

    T get(int l, int r) {  // sum on interval [l, r]
        if (l > r) return neutral_element;
        T res = neutral_element;
        for (l += size, r += size + 1; l < r; l >>= 1, r >>= 1) {
            if (l & 1) res = merge(res, tree[l++]);
            if (r & 1) res = merge(res, tree[--r]);
        }
        return res;
    }
};

void solve() {
    int n, k;
    cin >> n >> k;
    vector<int> a(n + 1), left(n + 1), right(n + 1);
    for (int i = 1; i <= n; i++) cin >> a[i];
    {
        stack<int> st;
        for (int i = 1; i <= n; i++) {
            while (!st.empty() and a[i] >= a[st.top()]) st.pop();
            left[i] = st.empty() ? 0 : st.top();
            st.push(i);
        }
        while (!st.empty()) st.pop();
        for (int i = n; i > 0; i--) {
            while (!st.empty() and a[i] >= a[st.top()]) st.pop();
            right[i] = st.empty() ? n + 1 : st.top();
            st.push(i);
        }
    }
    SegTree<int> last, sg, sg2; last.init(n + 1); sg2.init(n + 1);
    last.set(0, 0, false);
    vector<int> v(n + 1);
    for (int len = 1; len <= k; len++) {
        for (int &x: sg2.tree) x = inf;
        for (int i = 1; i <= n; i++) {
            int x = last.get(left[i], i - 1) + a[i];
            sg2.set(right[i] - 1, x, true);
            v[i] = sg2.get(i, n);
        }
        last.set(0, inf, false);
        for (int i = 1; i <= n; i++) last.set(i, v[i], false);
    }
    cout << last.get(n, n);
}

int main() {
    cin.tie(0)->sync_with_stdio(false);
#ifdef sunnatov
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    int q = 1;
//    cin >> q;
    while (q--) {
        solve();
        cout << '\n';
    }
}

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