30 lines
843 B
Ruby
30 lines
843 B
Ruby
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#Given an array of 0s and 1s in random order.Segregate 0s on left side and 1s on right side of the array.
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##Brute-force: Count 0s and rewrite array first with counted zeros then by 1
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#Time-complexity:O(n),Auxiliary-space:O(1)
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##Algorithm: Dutch National Flag Algorithm
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#Time-complexity:O(n),Auxiliary-space:O(1)
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def segregate(a)
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left=0
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right=a.length-1
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while left<right
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#Increment left index while we see 0 at left
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while a[left]== 0
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left+=1
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end
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#Decrement right index while we see 1 at right
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while a[right]==1
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right-=1
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end
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#Exchange arr[left] and arr[right]
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if left<right
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a[left],a[right]=a[right],a[left]
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left+=1
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right-=1
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end
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end
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return a
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end
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segregate([1,0,1,1,0,0]) # => [0, 0, 0, 1, 1, 1]
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