Submission #135264

#	Time	Username	Problem	Language	Result	Execution time	Memory
135264		pedro_sponchiado	Split the sequence (APIO14_sequence)	C++17	60 / 100	212 ms	131076 KiB

sequence

#include<bits/stdc++.h>
using namespace std;
const long long int INF=12345678912345678;
const int maxn=100010;
const int maxk=210;
int n, d;
int a[maxn];

long long int parc[maxn], parc_2[maxn];
long long int s_2[maxn];
long long int S_2(int i, int j){ 
	return s_2[j]-s_2[i-1]-parc[i-1]*(parc[j]-parc[i-1]);	
}
	
long long int dp[maxn][maxk];
int opt[maxn][maxk];

void resolve(int k, int ini, int fin, int opt_min, int opt_max){
	int m=(ini+fin)/2;
	dp[m][k]=INF;
	for(int l=opt_min; l<=opt_max; l++){
		if(dp[m][k]>dp[l][k-1]+S_2(l+1, m)){
			dp[m][k]=dp[l][k-1]+S_2(l+1, m);
			opt[m][k]=l;
		}	
	}
	
	if(ini!=fin){
		resolve(k, ini, m, opt_min, opt[m][k]);
		resolve(k, m+1, fin, opt[m][k], opt_max);	
	}
	return;
}

int main(){
	scanf("%d %d", &n, &d);
	for(int i=1; i<=n; i++){
		scanf("%d", &a[i]);
		parc[i]=parc[i-1]+a[i];
		parc_2[i]=parc_2[i-1]+a[i]*a[i];
		s_2[i]=(parc[i]*parc[i]-parc_2[i])/2;
	}
	
	for(int i=1; i<=n; i++) dp[i][0]=s_2[i];
	
	for(int k=1; k<=d; k++){
		resolve(k, 1, n, 1, n);	 
	}
	
	printf("%lld\n", s_2[n]-dp[n][d]); 
	
/*	for(int i=1; i<=n; i++){
		for(int k=1;k<=d; k++){
			printf("%d ", dp[i][k]);	
		}
		printf("\n");
	}
*/		
	int at=n;
	vector<int> aux;
	for(int i=d; i>=1; i--){
		aux.push_back(opt[at][i]);
		at=opt[at][i];	
	}
	for(int i=d-1; i>=0; i--) printf("%d ", aux[i]);
	
	return 0;	
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:36:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &d);
  ~~~~~^~~~~~~~~~~~~~~~~
sequence.cpp:38:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ~~~~~^~~~~~~~~~~~~

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