Submission #652674

#	Time	Username	Problem	Language	Result	Execution time	Memory
652674		Neos	K blocks (IZhO14_blocks)	C++14	0 / 100	43 ms	84076 KiB

blocks

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
typedef long long ll;
typedef pair<ll, ll> ii;

const int N = 1e5 + 7, M = 107;

int n, k, a[N], L[N], dp[N][M];
stack<int> st;

int T[N][M];
void upd(int i, int j, int v) {
    for (; i <= n; i += i & -i)
        T[i][j] = min(T[i][j], v);
}

int get(int i, int l, int r) {
    int res = 2e9;
    while (l <= r) {
        if (r - (r & -r) >= l) {
            res = min(res, T[r][i]);
            r -= r & -r;
        }
        else {
            res = min(res, dp[r][i]);
            --r;
        }
    }
    return res;
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];

    memset(dp, 0x3f, sizeof dp);
    memset(T, 0x3f, sizeof T);
    dp[0][1] = 0;
    for (int i = 1; i <= n; i++) {
        dp[i][1] = max(dp[i - 1][1], a[i]);
        upd(i, 1, dp[i][1]);
    }
    for (int i = 1; i <= n; i++) {
        while (st.size() && a[st.top()] <= a[i]) st.pop();
        if (st.empty()) {
            for (int j = 2; j <= k; j++) {
                dp[i][j] = get(j - 1, 1, i) + a[i];
                upd(i, j, dp[i][j]);
            }
        }
        else {
            for (int j = 2; j <= k; j++) {
                dp[i][j] = min(get(j - 1, st.top() + 1, i) + a[i], dp[L[i] - 1][j - 1] + a[L[i]]);
                upd(i, j, dp[i][j]);
            }
        }
        st.push(i);

        // f(i, j) = min(f(k - 1, j - 1) + max(a[k]..a[i]))
    }
    cout << dp[n][k];
}

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