18 lines
No EOL
532 B
CoffeeScript
18 lines
No EOL
532 B
CoffeeScript
# Uses a binary search algorithm to locate a value in the specified array.
|
|
window.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 |