Submission #100219

#	Time	Username	Problem	Language	Result	Execution time	Memory
100219		TadijaSebez	수열 (APIO14_sequence)	C++11	71 / 100	2056 ms	85240 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define ldb long double
const int N=100050;
const int K=205;
const ll inf=1e18;
struct Line{ ll k,n;int id;Line(){}Line(ll a, ll b, int c):k(a),n(b),id(c){}pair<ll,int> Get(ll x){ return mp(k*x+n,id);}} Hull[N];
ldb sec(Line a, Line b){ return b.k==a.k?-1e18:(ldb)(a.n-b.n)/(b.k-a.k);}
int hsz,ptr=1;
ll dp[N][2],sum[N];
int go[N][K];
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 j=1;j<=k;j++)
	{
		hsz=0;ptr=1;
		int c=j&1,p=c^1;
		Hull[++hsz]=Line(sum[j-1],dp[j-1][p]-sum[j-1]*sum[j-1],j-1);
		for(int i=j;i<=n;i++)
		{
			while(ptr<hsz && Hull[ptr].Get(sum[i])<Hull[ptr+1].Get(sum[i])) ptr++;
			tie(dp[i][c],go[i][j])=Hull[ptr].Get(sum[i]);
			Line l=Line(sum[i],dp[i][p]-sum[i]*sum[i],i);
			while(hsz>ptr && sec(Hull[hsz-1],Hull[hsz])>=sec(Hull[hsz],l)) hsz--;
			Hull[++hsz]=l;
		}
	}
	printf("%lld\n",dp[n][k&1]);
	vector<int> pos;
	for(int i=n,j=k;j;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:17:7: 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:18:62: 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