Submission #1102172

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102172		SP_Caramen	Sequence (BOI14_sequence)	C++14	0 / 100	1 ms	4692 KiB

sequence

#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;

int n, k;
int where[201][100001];
ll pref[100001]{0}, dp[2][100001], q[100001], l = 1, r = 1;

bool case1(int x, int y, int i) {
	return (dp[0][y] - dp[0][x] >= (pref[y] - pref[x]) * (pref[n] - pref[i]));
}

bool case2(int x, int y, int i) {
	return ((dp[0][y] - dp[0][x]) * (pref[i] - pref[y]) <=
	        (dp[0][i] - dp[0][y]) * (pref[y] - pref[x]));
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin >> n >> k;
	FOR(i, 1, n + 1) {
		int x;
		cin >> x;
		pref[i] = pref[i - 1] + x;
	}

	fill(dp[0], dp[0] + n + 1, 0);
	FOR(i, 1, k + 1) {
		q[r++] = 0;
		FOR(j, 1, n + 1) {
			while (r - l > 1 && case1(q[l], q[l + 1], j)) l++;

			ll x = q[l];
			dp[1][j] = dp[0][x] + (pref[j] - pref[x]) * (pref[n] - pref[j]);
			where[i][j] = x;

			while (r - l > 1 && case2(q[r - 2], q[r - 1], j)) r--;
			q[r++] = j;
		}
		l = r = 1;
		FOR(j, 1, n + 1) dp[0][j] = dp[1][j];
	}

	ll mx = -1;
	int indx = -1;
	FOR(i, 1, n + 1) {
		if (dp[0][i] > mx) mx = dp[0][i], indx = i;
	}
	cout << mx << '\n';
	FOR(i, 0, k) {
		cout << indx << ' ';
		indx = where[k - i][indx];
	}
	cout << '\n';
	return 0;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 33
• Subtask 3: 0 / 25
• Subtask 4: 0 / 33