Files
2018-02-02 04:16:08 -05:00

23 lines
615 B
CoffeeScript

# Uses a binary search algorithm to locate a value in the specified array.
binary_search = (items, value) ->
start = 0
stop = items.length - 1
pivot = Math.floor (start + stop) / 2
while items[pivot] isnt value and start < stop
# Adjust the search area.
stop = pivot - 1 if value < items[pivot]
start = pivot + 1 if value > items[pivot]
# Recalculate the pivot.
pivot = Math.floor (stop + start) / 2
# Make sure we've found the correct value.
if items[pivot] is value then pivot else -1
self.onmessage = (event) ->
data = event.data
binary_search(data.items, data.value)