Submission #523753

#	Time	Username	Problem	Language	Result	Execution time	Memory
523753		boykut	K blocks (IZhO14_blocks)	C++14	53 / 100	1099 ms	95404 KiB

blocks

#include <bits/stdc++.h>

using namespace std;

class segment_tree {
public:
	segment_tree(size_t s) {
		n = 1;
		while (n < s) n <<= 1;
		t.assign(2 * n, 1e18);
	}
	void update(int i, long long x, int v, int vl, int vr) {
		if (vl == vr) {
			t[v] = x;
		} else {
			int vm = vl + vr >> 1;
			if (i <= vm)
				update(i, x, v << 1, vl, vm);
			else
				update(i, x, v << 1 | 1, vm + 1, vr);
			t[v] = min(t[v << 1], t[v << 1 | 1]);
		}
	}
	void update(int i, long long x) {
		update(i, x, 1, 0, n - 1);
	}
	long long query(int l, int r, int v, int vl, int vr) {
		if (l > vr || vl > r) return 1e18;
		if (l <= vl && vr <= r) return t[v];
		int vm = vl + vr >> 1;
		auto q1 = query(l, r, v << 1, vl, vm);
		auto q2 = query(l, r, v << 1 | 1, vm + 1, vr);
		return min(q1, q2);
	}
	long long query(int l, int r) {
		return query(l, r, 1, 0, n - 1);
	}
private:
	int n;
	vector<long long> t;
};

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);
	segment_tree str(n + 1);
	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);
		str.update(i, dp[i][1]);
	}

	int K = k;
	for (int k = 2; k <= K; k++) {
		for (int i = 2; i <= n; i++) {
			int l = 1, r = i;
			while (l < r) {
				int m = (l + r) / 2;
				if (st.query(m, i) == a[i])
					r = m;
				else
					l = m + 1;
			}
			dp[i][k] = min(dp[i][k], dp[r - 1][k]);
			if (st.query(r, i) == a[i]) {
				long long mn = str.query(r - 1, i - 1);
				dp[i][k] = min(dp[i][k], mn + a[i]);
			}
		}
		for (int i = 1; i <= n; i++) {
			str.update(i, dp[i][k]);
		}
	}

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

	return 0;
}

Compilation message (stderr)

blocks.cpp: In constructor 'segment_tree::segment_tree(size_t)':
blocks.cpp:9:12: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
    9 |   while (n < s) n <<= 1;
      |          ~~^~~
blocks.cpp: In member function 'void segment_tree::update(int, long long int, int, int, int)':
blocks.cpp:16:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   16 |    int vm = vl + vr >> 1;
      |             ~~~^~~~
blocks.cpp: In member function 'long long int segment_tree::query(int, int, int, int, int)':
blocks.cpp:30:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   30 |   int vm = vl + vr >> 1;
      |            ~~~^~~~

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