46 lines
1.2 KiB
Ruby
46 lines
1.2 KiB
Ruby
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#Given an unsorted array of numbers ,return 1 if all the numbers are consecutive else return -1.
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#Approach 1: Using an auxiliary array to keep track of visited elements
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#Time-complexity:O(n),Auxiliary-space:O(n)
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def check_consecutive(a)
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len=a.length
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min=a.min
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max=a.max
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if len==(max-min+1)
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visited=Array.new(len,0)
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for i in 0...len
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return -1 unless visited[a[i]-min]==0
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visited[a[i]-min]=1
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end
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return 1
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end
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return -1
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end
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check_consecutive([1,3,3,2]) # => -1
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check_consecutive([1,4,3,2]) # => 1
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#Approach 2: Instead of using visited(auxiliary) array, we traverse for each index i and make a[i]-min -ve,
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#if a[i]-min is already -ve ,there is a repetition.
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#Time-complexity:O(n),Auxiliary-space:O(1)
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#Caveat: This algorithm modifies the content of the array and also this method might not work for negative numbers.
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def check_consecutive(a)
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len=a.length
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min=a.min
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max=a.max
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if len==(max-min+1)
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for i in 0...len
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j=(a[i]).abs-min
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if a[j]>0
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a[j]=-a[j]
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else
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return -1
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end
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end
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return 1
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end
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return -1
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end
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check_consecutive([1,3,3,2]) # => -1
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check_consecutive([1,4,3,2,5]) # => 1
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