File: code_binary_search.coffee

package info (click to toggle)
iceweasel 31.6.0esr-1
  • links: PTS, VCS
  • area: main
  • in suites: jessie-kfreebsd
  • size: 1,368,576 kB
  • sloc: cpp: 3,692,968; ansic: 1,797,194; python: 193,401; java: 180,622; asm: 133,557; xml: 89,288; sh: 71,748; perl: 22,087; makefile: 21,687; objc: 4,014; yacc: 1,995; pascal: 1,292; lex: 950; exp: 449; lisp: 228; awk: 211; php: 113; sed: 43; csh: 31; ada: 16; ruby: 3
file content (18 lines) | stat: -rw-r--r-- 532 bytes parent folder | download | duplicates (49) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
# 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