Submission #406511

#	Time	Username	Problem	Language	Result	Execution time	Memory
406511		yoavL	Split the sequence (APIO14_sequence)	C++14	71 / 100	95 ms	131076 KiB

sequence

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <queue>
#include <stack>
#include <bitset>
#include <math.h>
#include <fstream>
#include <iomanip>


using namespace std;

using ll = long long;
using ld = long double;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vvvvll = vector<vvvll>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vvvb = vector<vvb>;
using vld = vector<ld>;
using vvld = vector<vld>;
using vstr = vector<string>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using vvpll = vector<vpll>;
using pb = pair<bool, bool>;
using vpb = vector<pb>;
using vvpb = vector<vpb>;
using vi = vector<int>;
using vvi = vector<vi>;

const ll mod = (ll)1e9 + 7;
const ll inf = (ll)1e18;


#define FAST        ios_base::sync_with_stdio(0)
#define FASTIN		cin.tie(0)
#define FASTOUT		cout.tie(0)

#define upmin(a, b) a = min(a, b)
#define upmax(a, b) a = max(a, b)

#define pr(x) cout << x << endl;
#define prv(v) for(auto it = v.begin(); it != v.end(); ++it) cout << *it << " "; cout << endl;
#define prvv(v) for(auto it : v) { for(auto it2 : it) cout << it2 << " "; cout << endl; } cout << endl;
#define wpr(x) cout << #x << " = " << (x) << endl;
#define wprv(v) cout << #v << ": " << endl; for(auto it : v) cout << it << " "; cout << endl;
#define wprvv(v) cout << #v << ": " << endl; for(auto it : v) { for(auto it2 : it) cout << it2 << " "; cout << endl; } cout << endl;

#define rep(i,s,e) for(ll i = s; i < e; i++)
#define all(x) x.begin(),x.end()
#define pb push_back

ll n, k;
vll arr;
vvll dp, last;
vll p;

/*

dp[layer][i] = max sum using layer seperators and i is the last one (and it is AFTER i)

*/


void D_C(ll layer, ll l, ll r, ll optl, ll optr)
{
	if (l >= r) return;
	ll i = (l + r) / 2;
	ll opt = -1;
	ll optv = -1;
	//wpr(l);
	//wpr(r);
	//wpr(i);
	//wpr(optl);
	//wpr(optr);
	rep(j, optl, min(optr+1, i)) {
		//wpr(j);
		ll v = dp[layer - 1][j] + (p[i] - p[j]) * (p[n - 1] - p[i]);
		if (optv < v) {
			optv = v;
			opt = j;
		}
	}
	//wpr(opt);
	dp[layer][i] = optv;
	last[layer][i] = opt;
	D_C(layer, l, i, optl, opt);
	D_C(layer, i+1, r, opt, optr);
}

void solve()
{
	cin >> n >> k;
	arr.resize(n);
	rep(i, 0, n) cin >> arr[i];
	p.resize(n);
	p[0] = arr[0];
	rep(i, 1, n) p[i] = arr[i] + p[i - 1];
	dp.resize(k + 1, vll(n - 1, -1));
	last.resize(k + 1, vll(n - 1, -1));
	
	rep(i, 0, n - 1) {
		dp[1][i] = p[i] * (p[n - 1] - p[i]);
	}
	rep(l, 2, k + 1) {
		/*
		rep(i, 0, n-1) {
			rep(j, 0, i) {
				ll v = dp[l - 1][j] + (p[i] - p[j])*(p[n-1] - p[i]);
				if (dp[l][i] < v) {
					dp[l][i] = v;
					last[l][i] = j;
				}
			}
		}
		*/
		D_C(l, 1, n-1, 0, n);
	}
	//wprvv(dp);
	ll ans = -1;
	ll mxind = -1;
	rep(i, 0, n-1) {
		if (dp[k][i] > ans) {
			ans = dp[k][i];
			mxind = i;
		}
	}
	
	vll used;
	ll cur = mxind;
	ll left = k;
	while (cur != -1) {
		used.push_back(cur+1);
		cur = last[left][cur];
		left--;
	}
	reverse(used.begin(), used.end());
	pr(ans);
	prv(used);
	
}

int main()
{
	FAST;
	FASTIN; FASTOUT;
	solve();
}

/*

7 3 
4 1 3 4 0 2 3 


2 1 
0 123 

10 5 
1 1 1 1 1234 1 1 1 1 1234 


*/

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