Submission #523708

#	Time	Username	Problem	Language	Result	Execution time	Memory
523708		boykut	K blocks (IZhO14_blocks)	C++14	100 / 100	407 ms	94716 KiB

blocks

#include <bits/stdc++.h>

using namespace std;

class sparse_table {
public:
	sparse_table(vector<int>&a) : n(a.size()) {
		lg.resize(1 + n);
		lg[0] = lg[1] = 0;
		for (int i = 2; i <= n; i++)
			lg[i] = lg[i / 2] + 1;

		mx.assign(n, vector<int>(1 + lg[n]));
		for (int j = 0; j <= lg[n]; j++)
			for (int i = 0; i <= n - (1 << j); i++)
				if (j == 0) mx[i][j] = a[i];
				else mx[i][j] = max(mx[i][j-1], mx[i+(1<<(j-1))][j-1]);
	}
	int query(int l, int r) {
		int d = lg[r-l+1];
		return max(mx[l][d], mx[r-(1<<d)+1][d]);
	}
private:
	int n;
	vector<int> lg;
	vector<vector<int>> mx;
};


int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	int n, k;
	cin >> n >> k;
	vector<int> a(1 + n);
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	sparse_table st(a);
	vector<vector<long long>> dp(1 + n, vector<long long>(1 + k, 1e18));

	for (int i = 1; i <= n; i++) {
		dp[i][1] = st.query(1, i);
	}

	int K = k;
	for (int k = 2; k <= K; k++) {
		stack<pair<int, long long>> st;
		for (int i = 1; i <= n; i++) {
			long long mn = dp[i - 1][k - 1];
			while (!st.empty() && a[st.top().first] <= a[i]) {
				mn = min(mn, st.top().second);
				st.pop();
			}
			if (!st.empty())
				dp[i][k] = min(dp[i][k], dp[st.top().first][k]);
			dp[i][k] = min(dp[i][k], mn + a[i]);
			st.push({i, mn});
		}
	}

	cout << dp[n][k] << '\n';

	return 0;
}

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