Circle Of Numbers

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https://app.codesignal.com/tournaments/PmmyGsjEkvJbYK2XF/D

Consider integer numbers from 0 to n - 1 written down along the circle in such a way that the distance between any two neighboring numbers is equal (note that 0 and n - 1 are neighboring, too).

Given n and firstNumber, find the number which is written in the radially opposite position to firstNumber.

Example

For n = 10 and firstNumber = 2, the output should be
circleOfNumbers(n, firstNumber) = 7.

Input/Output

  • [execution time limit] 3 seconds (java)

  • [input] integer n

    A positive even integer.

    Guaranteed constraints:
    4 ≤ n ≤ 20.

  • [input] integer firstNumber

    Guaranteed constraints:
    0 ≤ firstNumber ≤ n - 1.

  • [output] integer

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