제출 #235907

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
235907		dlwocks31	수열 (APIO14_sequence)	C++17	0 / 100	22 ms	3976 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MX = 1e5+2;
int acc[MX], arr[MX], opt[201][MX];
ll dp[2][MX];
struct Line {
	ll a, b;
	int i;
	ll eval(int x) {
		return a*x + b;
	}
};
struct CHT {
	// increasing slope, increasing query, max query
	deque<Line> dq;
	int lst_x;
	CHT() {
		lst_x = 0;
	}
	void add(Line c) {
		while(dq.size() >= 2) {
			Line a = dq[dq.size()-2], b = dq.back();
			if((b.b-c.b)*(b.a-a.a) <= (a.b-b.b)*(c.a-b.a)) {
				dq.pop_back();
			} else {
				break;
			}
			//printf("add: dropped line %dx+%d\n", dq.back().a, dq.back().b);
		}
		//printf("added line %dx+%d\n", c.a, c.b);
		dq.push_back(c);
	}
	ll query(int x) {
		//printf("query with x=%d\n", x);
		while(dq.size() >= 2 && dq[0].eval(x) <= dq[1].eval(x)) {
			//printf("query: dropped line %dx+%d\n", dq[0].a, dq[0].b);
			dq.pop_front();
		}
		lst_x = x;
		return dq.front().eval(x);
	}
};
int32_t main() {
	ios::sync_with_stdio(0);cin.tie(0);
	int n, k;
	cin >> n >> k;
	for(int i=1; i<=n; i++) {
		cin >> arr[i];
		acc[i] += acc[i-1] + arr[i];
	}
	for(int i=1; i<=k; i++) {
		int c = i&1, p = c^1;
		CHT cht;
		for(int j=1; j<=n; j++) {
			cht.add({acc[j-1], dp[p][j-1]-acc[j-1]*acc[j-1], j});
			dp[c][j] = cht.query(acc[j]);
			opt[i][j] = cht.dq.front().i;
			//printf("at i=%d, j=%d, dp=%lld, opt=%d\n", i, j, dp[c][j], opt[i][j]);
		}
		//printf("----------------------\n");
	}
	ll ans = 0;
	vector<int> v;
	int a = k, b = n;
	while(a) {
		v.push_back(opt[a][b]-1);
		ans += (ll)(acc[b]-acc[opt[a][b]-1]) * (acc[opt[a][b]-1]);
		b = opt[a][b]-1;
		a--;
	}
	reverse(v.begin(), v.end());
	cout << ans << '\n';
	for(int t: v)
		cout << t << ' ';
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29