44 lines
1.1 KiB
Ruby
44 lines
1.1 KiB
Ruby
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#Given an array find maximum difference between two elements such that the karger appears after the smaller.
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#Approach 1: keep track of min so far and find the diff.
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#Time-complexity:O(n),Auxiliary-space:O(1)
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def max_diff(a)
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len=a.length
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min_so_far=a[0]
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diff=a[1]-a[0]
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for i in 1...len
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diff= a[i]-min_so_far if (a[i]-min_so_far > diff)
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min_so_far=a[i] if (a[i] < min_so_far)
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end
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return diff
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end
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max_diff([100, 10, 5, 91, 1, 8, 16, 21]) # => 86
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#Approach 2: find diff between adjacent elements,now find the max sum subarray of diff.
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#Time-complexity:O(n),Auxiliary-space:O(1)
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def max_diff(a)
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len=a.length
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diff=a[1]-a[0]
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curr_sum=diff
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max_sum=curr_sum
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for i in 1...len-1
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#calculate current diff
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diff=a[i+1]-a[i]
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#calculate current sum
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if curr_sum>0
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curr_sum+=diff
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else
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curr_sum=diff
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end
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#update max_sum
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max_sum=curr_sum if curr_sum>max_sum
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end
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return max_sum
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end
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min_diff([100, 10, 5, 91, 1, 8, 16, 21]) # => 86
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