Submission #40497

#	Time	Username	Problem	Language	Result	Execution time	Memory
40497		mohammad_kilani	Split the sequence (APIO14_sequence)	C++14	0 / 100	31 ms	24240 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define oo 1000000000
const double PI = acos(-1);
const int N = 10010 , K = 201;
int arr[N] , n , k , a , b , low , high , best[N][K]; 
long long dp[N][K] , sum[N] , cur1 , cur2 ;

void buildpath(int i,int j){
	if(i == n - 1 || j == k)
		return;
	for(int l=i+1;l<n;l++){
		if(dp[i][j] == dp[l][j+1] + (sum[l] - sum[i]) * (sum[n] - sum[l])){
			printf("%d ",l);
			buildpath(l,j+1);
			return;
		}
	}
}

int main(){
	scanf("%d%d",&n,&k);
	for(int i=0;i<n;i++){
		scanf("%d",&arr[i]);
		sum[i+1] = sum[i] + arr[i];
	}
	for(int i=0;i<k;i++)
		dp[n-1][i] = -1e17;
	for(int i=n-2;i>=0;i--){
		for(int j=0;j<k;j++){
			low = i + 1, high = n - 1 , a = i + 1;
			dp[i][j] = dp[a][j+1] + (sum[a] - sum[i]) * (sum[n] - sum[a]);
			best[i][j] = i + 1;
			while(high >= low){
				a = (low + low + high) / 3;
				b = (low + high + high) / 3;
				cur1 = dp[a][j+1] + (sum[a] - sum[i]) * (sum[n] - sum[a]);
				cur2 = dp[b][j+1] + (sum[b] - sum[i]) * (sum[n] - sum[b]);
				if(cur1 >= cur2){
					if(cur1 >= dp[i][j])
						best[i][j] = a;
					dp[i][j] = max(dp[i][j],cur1);
					low = a + 1;
				}
				else{
					if(cur2 >= dp[i][j])
						best[i][j] = b;
					dp[i][j] = max(dp[i][j],cur2);
					high = b - 1;
				}
			}
		}
	}
	printf("%lld\n",dp[0][0]);
 	int idx = 0;
 	for(int i=0;i<k;i++){
 		if(i > 0) putchar(' ');
 		printf("%d",best[idx][i]);
 		idx = best[idx][i];
 	}
 	puts("");
 	return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:23:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&k);
                     ^
sequence.cpp:25:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&arr[i]);
                      ^

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