🔀 合併排序視覺化

function mergeSort(arr):
  if arr.length <= 1: return arr
  mid = floor(arr.length / 2)
  left = mergeSort(arr[0..mid-1])
  right = mergeSort(arr[mid..end])
  return merge(left, right)

function merge(left, right):
  result = []
  while left and right 都有元素:
    取較小者放入 result
  將剩餘元素接到 result 後面