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