Submission #624044

#	Time	Username	Problem	Language	Result	Execution time	Memory
624044		Arnch	Split the sequence (APIO14_sequence)	C++17	71 / 100	91 ms	131072 KiB

sequence

// oooo
/*
 har chi delet mikhad bebar ~
 gitar o ba khodet nabar! ~
 ;Amoo_Hasan;
*/

#include<bits/stdc++.h>
#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")

using namespace std;

typedef long long ll;
typedef long double ld;

#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
#define mak make_pair

constexpr ll INF = 1e18, N = 1e5 + 10, MAXK = 2e2 + 10;

int n, k;
ll a[N], ps[N], dp[N][MAXK];
pair<ll, ll> par[N][MAXK];
bool mark[N];

ll cost(ll l, ll r) {
	return (ps[r] - ps[l - 1]) * (ps[r] - ps[l - 1]);
}

void Solve(int j, int l = 1, int r = n, int le = 1, int ri = n) {
	if(l > r) return;
	ll mid = (l + r) >> 1, opt = -1, best = INF;
	for(int i = max(0, le); i <= min(mid, 1ll * ri); i++) {
		if(dp[i - 1][j - 1] >= INF) continue;
		ll cur = dp[i - 1][j - 1] + cost(i, mid);
		if(best >= cur) {
			best = cur;
			opt = i;
		}
	}
	dp[mid][j] = best;
	par[mid][j] = mak(opt - 1, j - 1);

	Solve(j, l, mid - 1, le, opt), Solve(j, mid + 1, r, opt, ri);
}

int main() {
    ios :: sync_with_stdio(0), cin.tie(0);

	cin >>n >>k;
	for(int i = 1; i <= n; i++) cin >>a[i];

	for(int i = 1; i <= n; i++) ps[i] = ps[i - 1] + a[i];

	for(int i = 0; i <= n; i++)
		for(int j = 0; j <= k + 1; j++) dp[i][j] = INF;
	dp[0][0] = 0;

	for(int j = 1; j <= k + 1; j++) {
		Solve(j);
	}

	ll ans = ps[n] * ps[n];
	ans -= dp[n][k + 1];
	ans /= 2;

	cout<<ans <<endl;
	vector<int> pos;

	pair<ll, ll> p = mak(n, k + 1);
	while(p.second > 0) {
		p = par[p.first][p.second];
		if(p.first > 0) pos.push_back(p.first);
	}

	while(!pos.empty()) {
		cout<<pos.back() <<" ";
		pos.pop_back();
	}	

    return 0;
}

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