Submission #159700

#	Time	Username	Problem	Language	Result	Execution time	Memory
159700		DrSwad	K blocks (IZhO14_blocks)	C++17	100 / 100	349 ms	43000 KiB

blocks

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#endif

typedef long long ll;

typedef pair<int, int> pii;
#define x first
#define y second

const int N = int(1e5) + 10;
const int K = 105;
const int INF = int(1e9);

int n, k;
int a[N];
int l[N];
int dp[K][N];
int st[N], st_len;

int main() {
	#ifdef LOCAL
	freopen("in", "r", stdin);
	freopen("out", "w", stdout);
	#endif

	cin >> n >> k;
	for (int i = 1; i <= n; i++) scanf("%d", &a[i]);

	for (int i = 1; i <= n; i++) {
		int at = i - 1;
		while (at > 0 && a[at] < a[i]) at = l[at];
		l[i] = at;
	}

	fill(&dp[0][0], &dp[K][0], INF);
	dp[0][0] = 0;

	for (int _k = 1; _k <= k; _k++) {
		st_len = 0;
		for (int i = 0; i < _k; i++) {
			while (st_len > 0 && dp[_k - 1][st[st_len - 1]] >= dp[_k - 1][i]) st_len--;
			st[st_len++] = i;
		}
		for (int i = _k; i <= n; i++) {
			int at = lower_bound(st, st + st_len, l[i]) - st;
			dp[_k][i] = min(a[i] + dp[_k - 1][st[at]], dp[_k][l[i]]);

			while (st_len > 0 && dp[_k - 1][st[st_len - 1]] >= dp[_k - 1][i]) st_len--;
			st[st_len++] = i;
		}
	}

	cout << dp[k][n] << endl;

	return 0;
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:32:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
                               ~~~~~^~~~~~~~~~~~~

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