Submission #298680

#	Time	Username	Problem	Language	Result	Execution time	Memory
298680		errorgorn	Split the sequence (APIO14_sequence)	C++14	100 / 100	997 ms	82656 KiB

sequence

//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

struct line{
	ll m,c;
	int idx;
	
	ii get(ll x){
		return ii(m*x+c,idx);
	}
};

struct HULL{
	deque<line> dq;
	
	void reset(){
		dq={line({0,(ll)-1e18,-1})};
	}
	
	double POI(line i,line j){
		return (double)(i.c-j.c)/(j.m-i.m);
	}
	
	void add(line i){
		if (dq.back().m==i.m){
			if (dq.back().c<i.c) dq.pop_back();
			else return;
		}
		while (sz(dq)>=2 && POI(dq[sz(dq)-2],dq.back())>POI(dq.back(),i)) dq.pop_back();
		dq.push_back(i);
	}
	
	ii query(ll x){
		while (sz(dq)>=2 && POI(dq[0],dq[1])<x) dq.pop_front();
		return dq.front().get(x);
	}
} hull;

int n,k;
ll arr[100005];
ll memo[2][100005];
int p[205][100005];

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	cin>>n>>k;
	rep(x,1,n+1) cin>>arr[x],arr[x]+=arr[x-1];
	
	int a=0,b=1;
	rep(x,1,n+1) memo[a][x]=arr[x]*(arr[n]-arr[x]);
	
	k++;
	rep(y,2,k+1){
		hull.reset();
		rep(x,1,n+1){
			auto temp=hull.query(arr[x]-arr[n]);
			temp.fi+=arr[x]*(arr[n]-arr[x]);
			tie(memo[b][x],p[y][x])=temp;
			
			hull.add(line({arr[x],memo[a][x],x}));
		}
		swap(a,b);
	}
	
	cout<<memo[a][n]<<endl;
	int px=n;
	rep(x,k+1,2){
		cout<<p[x][px]<<" ";
		px=p[x][px];
	}
}

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