Submission #745184

#	Time	Username	Problem	Language	Result	Execution time	Memory
745184		Desh03	K blocks (IZhO14_blocks)	C++17	53 / 100	1069 ms	2388 KiB

blocks

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

struct segtree {
    vector<int> st;
    int sz;
    void init(int n) {
        sz = n;
        st.resize(sz << 1);
    }
    void upd(int u, int x) {
        for (st[u += sz] = x; u >>= 1;) st[u] = max(st[u << 1], st[u << 1 | 1]);
    }
    int qry(int l, int r) {
        int mx = 0;
        for (l += sz, r += sz + 1; l < r; l >>= 1, r >>= 1) {
            if (l & 1) mx = max(mx, st[l++]);
            if (r & 1) mx = max(mx, st[--r]);
        }
        return mx;
    }
} st;

vector<vector<long long>> dp;
int n;

void dnc(int k, int l, int r, int optl, int optr) {
    if (l > r) return;
    int mid = l + r >> 1;
    int opt = -1;
    for (int j = 0; j <= mid - 1; j++) {
        int mx = st.qry(j + 1, mid);
        if (dp[k][mid] > dp[k - 1][j] + mx)
            dp[k][mid] = dp[k - 1][j] + mx, opt = j;
    }
    dnc(k, l, mid - 1, optl, opt == -1 ? mid - 2 : opt);
    dnc(k, mid + 1, r, opt == -1 ? 0 : opt, optr);
}

int main() {
    int k, x;
    cin >> n >> k;
    st.init(n);
    dp = vector<vector<long long>> (k, vector<long long> (n, 1e18));
    for (int i = 0; i < n; i++) cin >> x, st.upd(i, x);
    for (int i = 0; i < n; i++) dp[0][i] = st.qry(0, i);
    for (int i = 1; i < k; i++) dnc(i, 0, n - 1, 0, n - 2);
    cout << dp[k - 1][n - 1] << '\n';
}

Compilation message (stderr)

blocks.cpp: In function 'void dnc(int, int, int, int, int)':
blocks.cpp:29:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   29 |     int mid = l + r >> 1;
      |               ~~^~~

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