1 // Sedgewick and Wayne, Algorithms, 4th ed. problem 1.3.44

2

3 // I would never use this in real life. It's far too inefficient.

4

5 #include "Buffer.hpp"

6

7 Buffer::Buffer( void ) :

8 cursor (0),

9 use_s1 (true)

10 {

11 }

12

13 void Buffer::insert( char c ) {

14 if ( use_s1 ) {

15 size_t i = 0;

16 size_t max = s1.size();

17 while ( i != cursor )

18 s2.push( s1.pop() );

19 s2.push( c );

20 while ( i < max )

21 s2.push( s1.pop() );

22 }

23 else {

24 size_t i = 0;

25 size_t max = s2.size();

26 while ( i != cursor )

27 s1.push( s2.pop() );

28 s1.push( c );

29 while ( i < max )

30 s1.push( s2.pop() );

31 }

32 }

33

34 char Buffer::get( void ) {

35 if ( use_s1 )

36 return s1.find( cursor ); // Need to add overloaded T find( size_t k) to Stack

37 else

38 return s2.find( cursor );

39 }

40

41 char Buffer::delete( void ) {

42 if ( use_s1 ) {

43 size_t i = 0;

44 size_t max = s1.size();

45 while ( i != cursor )

46 s2.push( s1.pop() );

47 ++i;

48 while ( i < max )

49 s2.push( s1.pop() );

50 }

51 else {

52 size_t i = 0;

53 size_t max = s2.size();

54 while ( i != cursor )

55 s1.push( s2.pop() );

56 ++i;

57 while ( i < max )

58 s1.push( s2.pop() );

59 }

60

61 if ( cursor > size() )

62 cursor = size();

63 }

64

65 void Buffer::left( size_t k ) {

66 if ( cursor < k )

67 cursor = 0;

68 else

69 cursor -= k;

70 }

71

72 void Buffer::right( size_t k ) {

73 if ( size() - cursor < k )

74 cursor = size();

75 else

76 cursor += k;

77 }

78

79 size_t Buffer::size( void ) {

80 if ( use_s1 )

81 return s1.size();

82 else

83 return s2.size();

84 }