Submission #241053

#	Time	Username	Problem	Language	Result	Execution time	Memory
241053		Nicholas_Patrick	Split the sequence (APIO14_sequence)	C++17	100 / 100	1630 ms	81776 KiB

sequence

#include <cstdio>
#include <queue>
#include <algorithm>
using namespace std;

int n, k;
vector <long long> a;
vector <long long> memo1, memo2;
vector <vector <int> > opt;
int i;
void solven(int l=1, int r=n, int ll=1, int rr=n){//[], []
	if(l>r)
		return;
	long long best=-1;
	int mid=(l+r)/2;
	long long&ret=memo2[mid];
	int&optt=opt[i][mid];
	optt=-1;
	ret=-1ll;
	for(int i = ll;i <= min(mid, rr);i ++){
		if(ret<(a[mid]-a[i])*(a[i]-a[0])+memo1[i]){
			optt=i;
			ret=(a[mid]-a[i])*(a[i]-a[0])+memo1[i];
		}
	}
	solven(l, mid-1, ll, optt);
	solven(mid+1, r, optt, rr);
}
long long solvenk(){
	opt.resize(k+1, vector <int> (n+1));
	memo1.assign(n+1, 0);
	memo2.assign(n+1, 0);
	for(i = 1;i <= k;i ++){
		solven();
		swap(memo1, memo2);
	}
	return memo1[n];
}
int main(){
	scanf("%d%d", &n, &k);
	a.resize(n+1);
	a[0]=0ll;
	for(i = 1;i <= n;i ++){
		scanf("%lld", &a[i]);
		a[i]+=a[i-1];
	}
	printf("%lld\n", solvenk());
	int j = n;
	vector <int> ans;
	for(i = k;i;i --){
		ans.push_back(opt[i][j]);
		j=opt[i][j];
	}
	sort(ans.begin(), ans.end());
	for(int i = 1;i < k;i ++){
		while(ans[i-1]>=ans[i]){
			ans[i]++;
		}
	}
	for(int i = 0;i < k;i ++){
		printf("%d%c", ans[i], i==k-1?'\n':' ');
	}
}

Compilation message (stderr)

sequence.cpp: In function 'void solven(int, int, int, int)':
sequence.cpp:14:12: warning: unused variable 'best' [-Wunused-variable]
  long long best=-1;
            ^~~~
sequence.cpp: In function 'int main()':
sequence.cpp:40:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &k);
  ~~~~~^~~~~~~~~~~~~~~~
sequence.cpp:44:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld", &a[i]);
   ~~~~~^~~~~~~~~~~~~~~

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