Binary Search

Procedure BinarySearch (VAR List: VECTOR; Low, High, LookFor: INTEGER; VAR Found: BOOLEAN; VAR Loc: INTEGER);

VAR Mid : INTEGER;

BEGIN {BinarySearch}

IF Low > High THEN Found := FALSE

ELSE { We may yet succeed }

BEGIN Mid := ( Low + High ) div 2;

IF LookFor = List[Mid] THEN

BEGIN Found := True; Loc := Mid END

ELSE

If LookFor < List[Mid]

BinarySearch ( List, Low, Mid-1, LookFor, Found, Loc)

ELSE { Look in Bottom Half }

BinarySearch ( List, Mid+1, High, LookFor, Found, Loc)

END; {BinarySearch}

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