23 lines
400 B
Factor
23 lines
400 B
Factor
USING: io formatting locals kernel math sequences unicode.case ;
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IN: balanced-brackets
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:: balanced ( str -- )
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0 :> counter!
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1 :> ok!
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str
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[ dup length 0 > ]
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[ 1 cut swap
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"[" = [ counter 1 + counter! ] [ counter 1 - counter! ] if
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counter 0 < [ 0 ok! ] when
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]
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while
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drop
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ok 0 =
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[ "NO" ]
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[ counter 0 > [ "NO" ] [ "YES" ] if ]
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if
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print ;
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readln
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balanced
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