/examples/beautiful_code/binary_search.coffee

http://github.com/jashkenas/coffee-script · CoffeeScript · 16 lines · 11 code · 2 blank · 3 comment · 4 complexity · 73fff5ea64ff0f5dcf590da23dc142e1 MD5 · raw file 

    

  1. # Beautiful Code, Chapter 6.
    2. 

  2. # The implementation of binary search that is tested.
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  3. 

  4. # Return the index of an element in a sorted list. (or -1, if not present)
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  5. index = (list, target) ->
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  6.   [low, high] = [0, list.length]
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  7.   while low < high
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  8.     mid = (low + high) >> 1
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  9.     val = list[mid]
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  10.     return mid if val is target
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  11.     if val < target then low = mid + 1 else high = mid
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  12.   return -1
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  13. 

  14. console.log 2 is index [10, 20, 30, 40, 50], 30
    15. 

  15. console.log 4 is index [-97, 35, 67, 88, 1200], 1200
    16. 

  16. console.log 0 is index [0, 45, 70], 0
    17.