A spin off problem from Educational Div2 91 — D

Правка en4, от Dsxv, 2020-07-12 23:55:01

Hi!

While solving Div2 D, I came across another problem (not related to solving the actual problem though) :

Given a binary array A of size N, you are required to remove all the occurrence of 1 in the array only using the following step:

  • Select any subarray of size K ( K <= N ) and remove it from the array. After removing it, the adjacent parts (if any) will be joined as a single array.

Let's define Ans as the size remaining array after removing all the occurrence of 1 in A. Find the maximum value of Ans or say that it's impossible.

eg,

A : [1, 0, 0, 1, 0, 0, 1, 1] ,
K = 2
We have, Ans = 2 (In the end 3rd and 6th 0 's in the remaining array, Indexing from 1), multiple answers possible.

A simple greedy solution can be to select a window with a maximum frequency of 1s and remove it, continue doing this until all 1s are gone or say it's impossible. O(n^2) Edit: Wrong approach sorry :p

I'd like to hear your approach to this problem.

Thanks in advance!

История

 
 
 
 
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  Rev. Язык Кто Когда Δ Комментарий
en4 Английский Dsxv 2020-07-12 23:55:01 63 Tiny change: '**O(n^2)**, </strike> Edit: Wrong app' -> '**O(n^2)** </strike> **Edit:** Wrong app'
en3 Английский Dsxv 2020-07-12 21:46:42 38 Tiny change: '**O(n^2)** \n\nI'd li' -> '**O(n^2)**( not sure of the correctness :( )\n\nI'd li'
en2 Английский Dsxv 2020-07-12 21:38:12 259 Tiny change: 's problem with a be' -> 's problem possibly with a be' (published)
en1 Английский Dsxv 2020-07-12 21:12:20 901 Initial revision (saved to drafts)