Submission #108133

#	Time	Username	Problem	Language	Result	Execution time	Memory
108133		maruii	Split the sequence (APIO14_sequence)	C++14	100 / 100	594 ms	85880 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define ff first
#define ss second

int A[100001], S[100001];
ll dp[2][100001];
pair<int, ll> line[2][100001];
int cnt[2], idx[2][100001];
int pre[201][100001];

inline ll f(int t, int i, int x){
	return 1ll * line[t][i].ff * x + line[t][i].ss;
}
inline double crs(pair<int, ll> x, pair<int, ll> y){
	return (double)(y.ss - x.ss) / (x.ff - y.ff);
}

int main(){
	ios_base::sync_with_stdio(0), cin.tie(0);
	int N, K; cin>>N>>K;
	for(int i=0; i<N; ++i) cin>>A[i];
	S[0] = A[0];
	for(int i=1; i<N; ++i) S[i] = S[i-1] + A[i];

	idx[1][1] = N;
	for(int k=0; k<=K; ++k){
		int t = k&1;
		cnt[t] = 0;
		idx[!t][cnt[!t]] = N;
		for(int i=k, j=0; i<N; ++i){
			while(idx[!t][j+1] < i && f(!t, j, S[i]) <= f(!t, j+1, S[i])) ++j;
			dp[t][i] = f(!t, j, S[i]);
			pre[k][i] = idx[!t][j];
			pair<int, ll> newLine = {S[i], dp[t][i]-1ll*S[i]*S[i]};
			while(cnt[t] > 1 && crs(line[t][cnt[t]-1], line[t][cnt[t]-2]) >= crs(line[t][cnt[t]-2], newLine)) --cnt[t];
			idx[t][cnt[t]] = i;
			line[t][cnt[t]++] = newLine;
		}
	}

	vector<int> ans;
	for(int i=N-1, cnt=K; cnt; --cnt) ans.push_back(i = pre[cnt][i]);
	reverse(ans.begin(), ans.end());
	cout<<dp[K&1][N-1]<<'\n';
	for(auto i: ans) cout<<i+1<<' ';
	return 0;
}

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