Submission #250353

#	Time	Username	Problem	Language	Result	Execution time	Memory
250353		Evirir	Split the sequence (APIO14_sequence)	C++17	60 / 100	2097 ms	95992 KiB

sequence

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define watch(x) cout<<(#x)<<"="<<(x)<<'\n'
#define mset(d,val) memset(d,val,sizeof(d))
#define setp(x) cout<<fixed<<setprecision(x)
#define forn(i,a,b) for(int i=(a);i<(b);i++)
#define fore(i,a,b) for(int i=(a);i<=(b);i++)
#define pb push_back
#define F first
#define S second
#define pqueue priority_queue
#define fbo find_by_order
#define ook order_of_key
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
typedef long double ld;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> pbds;
void amin(ll &a, ll b){ a=min(a,b); }
void amax(ll &a, ll b){ a=max(a,b); }
void YES(){cout<<"YES\n";} void NO(){cout<<"NO\n";}
void SD(int t=0){ cout<<"PASSED "<<t<<endl; }
const ll INF = ll(1e18);
const int MOD = 998244353;

struct Line{
	mutable ll m,b,p;
	bool operator<(const Line& o) const { return m < o.m; }
	bool operator<(ll x) const { return p < x; }
};

struct ConvexHullDynamic: multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	const ll inf = LLONG_MAX;
	bool Max = 1;
	
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) { x->p = inf; return false; }
		if (x->m == y->m) x->p = x->b > y->b ? inf : -inf;
		else x->p = div(y->b - x->b, x->m - y->m);
		return x->p >= y->p;
	}
	void addline(ll m, ll b) {
		if(!Max) { m=-m; b=-b; }
		auto z = insert({m, b, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	Line query(ll x) {
		if(empty()) return Line{0,0,0};
		auto l = *lower_bound(x);
		return l;
	}
};

const bool DEBUG = 0;
const int MAXN = 100005;
const int MAXK = 205;

int n,K;
ll s[MAXN], dp[MAXK][MAXN], nxt[MAXK][MAXN];

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	
	cin>>n>>K;
	forn(i,0,n){
		cin>>s[i];
		if(i>0) s[i]+=s[i-1];
	}
	
	ConvexHullDynamic cht;
	
	fore(i,1,K)
	{
		cht.clear();
		forn(j,0,n)
		{
			Line res = cht.query(s[j]);
			nxt[i][j]=res.m;
			dp[i][j] = res.m * s[j] + res.b;
			cht.addline(s[j], dp[i-1][j]-s[j]*s[j]);
		}
	}
	
	vi ans;
	int cur=n-1;
	for(int i=K;i>=1;i--){
		forn(j,0,cur){
			if(s[j]==nxt[i][cur]){
				ans.pb(j);
				cur=j;
				break;
			}
		}
	}
	
	cout<<dp[K][n-1]<<'\n';
	for(ll x: ans) cout<<x+1<<" ";
	cout<<'\n';
	
	return 0;
}

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