Test Writing: Count Decreasing Sequences

Created By: Rohith Sanjay

/ Version: 2024.9.0

Write a method caled numDecrease which takes in one argument: an IntArray? called input. Your solution returns the number (an Int) of decreasing sequences in input. A decreasing sequence is a sequence (2 or more consecutive elements) in input where element n+1 has a value strictly less than element n. Things to note: if element n+1 is equal to element n, then this represents two different sequences. If input is null or empty, return 0. For example, the array [1, 2, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2] has 2 decreasing sequences (decreasing sequences in bold). The array [1, 2, 3, 3, 4, 5, 5, 5, 6] has no decreasing sequences. The array [8, 7, 6, 6, 5, 4, 3, 3, 2] has 3 decreasing sequences ([8, 7, 6], [6, 5, 4, 3], and [3, 2]). The array [1] has no decreasing sequences, but [3, 2] has 1 decreasing sequence. Some Tips: Loop through the array in pairs of elements. Look at element n and element n+1 to determine if the current pair is increasing or decreasing. Also, keep track of when a decreasing sequence starts, meaning you need to keep track of whether the current sequence is decreasing or not.

Test Design Challenge

You're challenge is to write tests for this problem described above.

• Provide a method named test that accepts no arguments and does not return a value.
• If the implementation of the class described above is incorrect, your test method should throw an exception.
• If it is correct, do not throw an exception.
• You may want to use Kotlin's assert or check methods