Submission #551955

#	Time	Username	Problem	Language	Result	Execution time	Memory
551955		QwertyPi	Split the sequence (APIO14_sequence)	C++14	100 / 100	751 ms	84064 KiB

sequence

#include <bits/stdc++.h>
#define fi first
#define se second
#define int long long
using namespace std;
typedef pair<int, int> pii;
const int N = 1e5 + 5, K = 201;
const long long inf = 1e18;
int A[N], s[N];
int32_t bf[K][N];
int dp[2][N];
int m[N], c[N];
deque<int> cht;

int f(int id, int v){
	return m[id] * v + c[id];
}

bool cmp(int x, int y, int z){
	return (c[x] - c[z]) * (m[y] - m[x]) <= (c[x] - c[y]) * (m[z] - m[x]);
}

void add(int sl, int co, int id){
	m[id] = sl, c[id] = co;
	while(cht.size() >= 2 && cmp(cht[cht.size() - 2], cht[cht.size() - 1], id)){
		cht.pop_back();
	}
	cht.push_back(id);
}

pii qry(int v){
	while(cht.size() >= 2 && f(cht[1], v) >= f(cht[0], v)) cht.pop_front();
	return {cht[0], f(cht[0], v)};
}

int32_t main(){
	int n, k;
	cin >> n >> k;
	for(int i = 0; i < n; i++){
		cin >> A[i]; 
	}
	for(int i = 0; i < n; i++) s[i + 1] = s[i] + A[i];
	for(int i = 0; i < k; i++){
		cht.clear();
		for(int j = 0; j < n; j++){
			add(s[j], dp[i % 2][j] - s[j] * s[j], j);
			pii val = qry(s[j + 1]);
			bf[i + 1][j + 1] = val.fi;
			dp[(i + 1) % 2][j + 1] = val.se;
		}
	}
	
	int ans = dp[k % 2][n];
	vector<int> cut;
	int v = n;
	for(int j = k; j >= 1; j--){
		v = bf[j][v];
		cut.push_back(v);
	}
	cout << ans << endl;
	reverse(cut.begin(), cut.end());
	for(auto i : cut){
		cout << i << ' ';
	}
	cout << endl;
}

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