Problem
Given a circular array arr
and an integer startIndex
, return a generator object gen
that yields values from arr
.
The first time gen.next()
is called on the generator, it should should yield arr[startIndex]
.
Each subsequent time gen.next()
is called, an integer jump
will be passed into the function (Ex: gen.next(-3)
).
- If
jump
is positive, the index should increase by that value, however if the current index is the last index, it should instead jump to the first index. - If
jump
is negative, the index should decrease by the magnitude of that value, however if the current index is the first index, it should instead jump to the last index.
Example 1:
Input: arr = [1,2,3,4,5], steps = [1,2,6], startIndex = 0 Output: [1,2,4,5] Explanation: const gen = cycleGenerator(arr, startIndex); gen.next().value; // 1, index = startIndex = 0 gen.next(1).value; // 2, index = 1, 0 -> 1 gen.next(2).value; // 4, index = 3, 1 -> 2 -> 3 gen.next(6).value; // 5, index = 4, 3 -> 4 -> 0 -> 1 -> 2 -> 3 -> 4
Example 2:
Input: arr = [10,11,12,13,14,15], steps = [1,4,0,-1,-3], startIndex = 1 Output: [11,12,10,10,15,12] Explanation: const gen = cycleGenerator(arr, startIndex); gen.next().value; // 11, index = 1 gen.next(1).value; // 12, index = 2 gen.next(4).value; // 10, index = 0 gen.next(0).value; // 10, index = 0 gen.next(-1).value; // 15, index = 5 gen.next(-3).value; // 12, index = 2
Example 3:
Input: arr = [2,4,6,7,8,10], steps = [-4,5,-3,10], startIndex = 3 Output: [7,10,8,4,10] Explanation: const gen = cycleGenerator(arr, startIndex); gen.next().value // 7, index = 3 gen.next(-4).value // 10, index = 5 gen.next(5).value // 8, index = 4 gen.next(-3).value // 4, index = 1 gen.next(10).value // 10, index = 5
Constraints:
1 <= arr.length <= 104
1 <= steps.length <= 100
-104 <= steps[i], arr[i] <= 104
0 <= startIndex < arr.length