Class Solution
Hard
You are given a 0-indexed array arr
consisting of n
positive integers, and a positive integer k
.
The array arr
is called K-increasing if arr[i-k] <= arr[i]
holds for every index i
, where k <= i <= n-1
.
- For example,
arr = [4, 1, 5, 2, 6, 2]
is K-increasing fork = 2
because:arr[0] <= arr[2] (4 <= 5)
arr[1] <= arr[3] (1 <= 2)
arr[2] <= arr[4] (5 <= 6)
arr[3] <= arr[5] (2 <= 2)
- However, the same
arr
is not K-increasing fork = 1
(becausearr[0] > arr[1]
) ork = 3
(becausearr[0] > arr[3]
).
In one operation , you can choose an index i
and change arr[i]
into any positive integer.
Return the minimum number of operations required to make the array K-increasing for the given k
.
Example 1:
Input: arr = [5,4,3,2,1], k = 1
Output: 4
Explanation:
For k = 1, the resultant array has to be non-decreasing.
Some of the K-increasing arrays that can be formed are [5, 6 , 7 , 8 , 9 ], [1 , 1 , 1 , 1 ,1], [2 , 2 ,3, 4 , 4 ]. All of them require 4 operations.
It is suboptimal to change the array to, for example, [6 , 7 , 8 , 9 , 10 ] because it would take 5 operations.
It can be shown that we cannot make the array K-increasing in less than 4 operations.
Example 2:
Input: arr = [4,1,5,2,6,2], k = 2
Output: 0
Explanation:
This is the same example as the one in the problem description.
Here, for every index i where 2 <= i <= 5, arr[i-2] <= arr[i].
Since the given array is already K-increasing, we do not need to perform any operations.
Example 3:
Input: arr = [4,1,5,2,6,2], k = 3
Output: 2
Explanation:
Indices 3 and 5 are the only ones not satisfying arr[i-3] <= arr[i] for 3 <= i <= 5.
One of the ways we can make the array K-increasing is by changing arr[3] to 4 and arr[5] to 5.
The array will now be [4,1,5, 4 ,6, 5 ].
Note that there can be other ways to make the array K-increasing, but none of them require less than 2 operations.
Constraints:
1 <= arr.length <= 105
1 <= arr[i], k <= arr.length
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Constructor Summary
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Method Summary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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Solution
public Solution()
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Method Details
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kIncreasing
public int kIncreasing(int[] arr, int k)
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