You have a bomb to defuse, and your time is running out! Your informer will provide you with a circular array code of length of n and a key k.
To decrypt the code, you must replace every number. All the numbers are replaced simultaneously.
If k > 0, replace the ith number with the sum of the next k numbers.
If k < 0, replace the ith number with the sum of the previous k numbers.
If k == 0, replace the ith number with 0.
As code is circular, the next element of code[n-1] is code, and the previous element of code is code[n-1].
Given the circular array code and an integer key k, return the decrypted code to defuse the bomb!
Explanation: Each number is replaced by the sum of the next 3 numbers. The decrypted code is [7+1+4, 1+4+5, 4+5+7, 5+7+1]. Notice that the numbers wrap around.
This is an easy challenge, we only need to iterate the array and calculate the previous(or latter)
Note for the negative index, we need to add
code.size() and then
mod it into range
Time complexity is O(N*k)
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