Theo, this solution, if I'm parsing it correctly, assumes that all duplicate records are 'stacked' together... ie, all 1111 lines occur one after another, correct? I pretty much discarded that pattern as soon as I saw it, since rarely do the problem sets order themselves up that conveniently. ;)
He said in the specification that the input file was already sorted.

In reply to Re: Re: Re: Separate duplicate and unique records by Thelonius
in thread Separate duplicate and unique records by wsee

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