Submission #1066469

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066469		beaconmc	Split the sequence (APIO14_sequence)	C++14	100 / 100	1149 ms	85532 KiB

sequence

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

ll dp[100001][2];
int prevs[100001][201];

deque<vector<ll>> sus;


bool sussy(ll a, ll b, ll mi, ll ci){
	return (sus[a][1] - ci) * (sus[a][0] - sus[b][0]) <= (mi - sus[a][0]) * (sus[b][1] - sus[a][1]);
}

int main(){
	

	ll n,k;
	cin >> n >> k;
	vector<ll> arr(n);
	vector<ll> pref(n);
	FOR(i,0,n) cin >> arr[i];
	pref[0] = arr[0];
	FOR(i,1,n) pref[i] = pref[i-1]+arr[i];

	FOR(i,0,100001)FOR(j,0,2) dp[i][j] = -1000000000;



	




	dp[0][0] = 0;
	FOR(j,1,k+1){
		sus.clear();
		sus.push_back({-pref[0]+arr[0], dp[0][0], 0});
		FOR(i,1,n+1){

			ll temp = (pref[n-1] - pref[i-1]);

			while (sus.size() >= 2 &&  (temp * sus[1][0] + sus[1][1]) > (temp * sus[0][0] + sus[0][1])){
				sus.pop_front();
			}

			ll ans = temp * sus[0][0] + sus[0][1] + (pref[n-1] - pref[i-1]) * pref[i-1];

			if (dp[i][1] < ans){
				dp[i][1] = ans;
				prevs[i][j] = sus[0][2];
			}

			while (sus.size()>=2 && sussy(sus.size()-2, sus.size()-1, (-pref[i]+arr[i]), dp[i][0])) {
				sus.pop_back();
			}
			sus.push_back({(-pref[i]+arr[i]), dp[i][0], i});
		}
		FOR(i,0,n+1) dp[i][0] = dp[i][1];
		FOR(i,0,n+1) dp[i][1] = -1000000000;
	}




	ll maxi = -1;
	ll pos = -1;
	FORNEG(i,n-1,-1) if (dp[i][0] > maxi) maxi = dp[i][0], pos = i;

	cout << dp[pos][0] << endl;

	FOR(i,0,k){
		ll sus = prevs[pos][k-i];
		cout << pos << " ";
		pos  = sus;
		
	}

}

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