34 lines
606 B
Ruby
34 lines
606 B
Ruby
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#Reversal Algorithm for array rotation
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#Time complexity : O(n), Auxiliary space: O(1)
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def left_rotate_array(a,d) #Input array "a" and rotation by "d" elemets
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n=a.length
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if n>0
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if d>n # if d>n ,we take modulo n
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d%=n
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end
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reverse(a,0,d-1)
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reverse(a,d,n-1)
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reverse(a,0,n-1)
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end
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return a
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end
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def reverse(a,first,last) #Utility function for reversing array
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i=first
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j=last
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while i<j
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temp=a[i]
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a[i]=a[j]
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a[j]=temp
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i+=1
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j-=1
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end
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return a
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end
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