Submission #100211

#	Time	Username	Problem	Language	Result	Execution time	Memory
100211		TadijaSebez	수열 (APIO14_sequence)	C++11	71 / 100	2051 ms	85304 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
const int N=100050;
const int K=205;
const ll inf=1e18;
struct Line{ ll k,n;int id;Line(ll a=0, ll b=0, int c=0):k(a),n(b),id(c){}pair<ll,int> Get(ll x){ return mp(k*x+n,id);}} Hull[N];
ll sec(Line a, Line b)
{
	ll p=a.n-b.n,q=b.k-a.k;
	if(q<0) p=-p,q=-q;
	if(p>0) return (p+q-1)/q;
	else return p/q;
}
int hsz,ptr=1;
void AddLine(Line l)
{
	if(hsz>=ptr && Hull[hsz].k==l.k && Hull[hsz].n<l.n) hsz--;
	if(hsz>=ptr && Hull[hsz].k==l.k) return;
	while(hsz>ptr && sec(Hull[hsz-1],Hull[hsz])>=sec(Hull[hsz],l)) hsz--;
	Hull[++hsz]=l;
}
pair<ll,int> Get(ll x){ while(ptr<hsz && Hull[ptr].Get(x)<Hull[ptr+1].Get(x)) ptr++;return Hull[ptr].Get(x);}
ll dp[N][2],sum[N];
int go[N][K];
void Solve(int k, int n)
{
	hsz=0;ptr=1;
	int c=k&1,p=c^1;
	AddLine(Line(sum[k-1],dp[k-1][p]-sum[k-1]*sum[k-1],k-1));
	for(int i=k;i<=n;i++)
	{
		tie(dp[i][c],go[i][k])=Get(sum[i]);
		AddLine(Line(sum[i],dp[i][p]-sum[i]*sum[i],i));
	}
}
int main()
{
	int n,k;
	scanf("%i %i",&n,&k);k++;
	for(int i=1;i<=n;i++) scanf("%lld",&sum[i]),sum[i]+=sum[i-1],dp[i][0]=-inf;
	for(int i=1;i<=k;i++) Solve(i,n);
	printf("%lld\n",dp[n][k&1]);
	vector<int> pos;
	for(int i=n,j=k;i;i=go[i][j],j--) pos.push_back(i);
	reverse(pos.begin(),pos.end());
	pos.pop_back();
	for(int i:pos) printf("%i ",i);
	return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:41:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i %i",&n,&k);k++;
  ~~~~~^~~~~~~~~~~~~~~
sequence.cpp:42:62: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;i++) scanf("%lld",&sum[i]),sum[i]+=sum[i-1],dp[i][0]=-inf;
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

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