제출 #973425

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
973425		TranGiaHuy1508	수열 (APIO14_sequence)	C++17	71 / 100	359 ms	131072 KiB

sequence

#include <bits/stdc++.h>
using namespace std;

void main_program();

signed main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	main_program();
}

using ll = long long;
const ll inf = 1e18;

struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k < o.k; }
	bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
};

int n, k;
vector<ll> v, pfx;

void main_program(){
	cin >> n >> k;

	v.resize(n + 1);
	for (int i = 1; i <= n; i++) cin >> v[i];

	pfx.resize(n + 1);
	for (int i = 1; i <= n; i++) pfx[i] = pfx[i-1] + v[i];

	vector<vector<ll>> dp(k + 2, vector<ll>(n + 1, -inf));
	dp[0][0] = 0;
	for (int j = 1; j <= k + 1; j++){
		LineContainer cht;
		for (int i = 1; i <= n; i++){
			// Add line (pfx[i-1] * S + dp[i-1] - pfx[i-1]^2)
			cht.add(pfx[i-1], dp[j-1][i-1] - pfx[i-1] * pfx[i-1]);

			// Find answer
			dp[j][i] = cht.query(pfx[i]);
		}
	}

	cout << dp[k + 1][n] << "\n";

	vector<int> splits;

	int crr = n;
	for (int j = k + 1; j > 0; j--){
		for (int i = crr - 1; i >= 0; i--){
			if (pfx[i] * pfx[crr] + dp[j-1][i] - pfx[i] * pfx[i] == dp[j][crr]){
				crr = i;
				if (j > 1) splits.push_back(crr);
				break;
			}
		}
	}

	reverse(splits.begin(), splits.end());
	for (auto elem: splits) cout << elem << " ";
	cout << "\n";
}

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