16 lines
499 B
CoffeeScript
16 lines
499 B
CoffeeScript
# Beautiful Code, Chapter 6.
|
|
# The implementation of binary search that is tested.
|
|
|
|
# Return the index of an element in a sorted list. (or -1, if not present)
|
|
index: (list, target) ->
|
|
[low, high]: [0, list.length]
|
|
while low < high
|
|
mid: (low + high) >> 1
|
|
val: list[mid]
|
|
return mid if val is target
|
|
if val < target then low: mid + 1 else high: mid
|
|
return -1
|
|
|
|
puts 2 is index([10, 20, 30, 40, 50], 30)
|
|
puts 4 is index([-97, 35, 67, 88, 1200], 1200)
|
|
puts 0 is index([0, 45, 70], 0) |