Am I reading the Contains Duplicate III question correctly?


  • 1
    N

    Hi all, newbie here. I am getting a "wrong answer" response for the following test case:

    Input:	[-3,3], 2, 4
    Output:	true
    Expected:	false
    

    So, according to the question:

    Given an array of integers, find out whether there are two distinct
    indices i and j in the array such that the difference between nums[i]
    and nums[j] is at most t and the difference between i and j is at most
    k.

    My interpretation of the question is that I am supposed to find a pair of element indices (i, j) whose difference is at most t=4, and the indices of these elements cannot be more than k=2 apart.

    So, taking i = 0 and j = 1, I get:

    nums[0] - nums[1] => -3 - 3 = -6 
    

    which seems to satisfy the "at most t" (t=4) requirement, since -6 is less than 4. Can the author or someone please point out my mistake in interpreting the question?

    Thanks much,

    • K.

  • 0
    S

    the difference "at most t" means the absolute value, |-6| > 4, so it doesn't satisfy the requirement.


  • 1
    J

    One another testcase that's puzzling me is,

    Input:	[7,1,3], 2, 3
    Output:	false
    Expected:	true
    

    How can the correct solution to this testcase be true?


  • 0
    B

    the difference between 1 and 3 is 2(<=3) and difference between their indices 1(<=2). That's why the correct answer is true


  • 0
    L

    You just need to think in terms of distances between both indices and values. So in your first example: [-3,3], 2, 4. You have abs(i-j) = 1 <= 2 so that is fine, however abs(nums[i]-nums[j]) = 6 > 4 (for i=0 and j=1), so that is why the expected is false. If you take i=1 and j=0 you have abs(i-j) = 1 <= 2, yet abs(nums[i] - nums[j]) = 6 > 4.

    I think that the description of this code challenge could be improved to clarify what exactly is expected. I found the description of the task unclear.


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