/**
 *
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

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

function circleOfNumbers(n, firstNumber) {
  let circle = []
  let halfOfN = n / 2
  for (let index = 0; index < n; index++) {
    circle.push(index)
  }
  if (firstNumber < halfOfN) {
    return firstNumber + circle[halfOfN]
  }
  return circle[firstNumber - halfOfN]
}

test('circle Of Numbers', () => {
  expect(circleOfNumbers(10, 2)).toEqual(7)
})