Set: Difference between revisions

Line 36:

An alternative hash-based solution could use the Hashed_Maps package from Ada.Containers.

<lang Ada>with ~~Ada~~.~~Text_IO~~, ~~Ada.Containers~~.~~Ordered_Sets~~;

<lang Ada>with ada.containers.ordered_sets, ada.text_io;

use ada.text_io;

procedure ~~Set_Demo~~ is

procedure set_demo is

package cs is new ada.containers.ordered_sets (character); use cs;

function "+" (s : string) return set is

package CS is new Ada.Containers.Ordered_Sets(Character); use CS;

(if s = "" then empty_set else Union(+ s(s'first..s'last - 1), To_Set (s(s'last))));

package IO renames Ada.Text_IO;

function "-" (s : Set) return string is

-- helper functions for string to something conversion, and vice versa

~~function~~ To_Set~~(S:~~ ~~String~~) ~~return~~ ~~Set is~~

(if s = empty_set then "" else - (s - To_Set (s.last_element)) & s.last_element);

s1, s2 : set;

Result: Set;

begin

⚫

loop

for I in S'Range loop

put ("s1= ");

begin

s1 := + get_line;

Result.Insert(S(I));

⚫

exit when s1 = +"Quit!";

-- raises Constraint_Error if S(I) is already in Result

put ("s2= ");

exception

s2 := + get_line;

when Constraint_Error => null;

~~end;~~

Put_Line("Sets [" & (-s1) & "], [" & (-s2) & "] of size"

⚫

& S1.Length'img & " and" & s2.Length'img & ".");

⚫

end loop;

⚫

Put_Line("Intersection: [" & (-(Intersection(S1, S2))) & "],");

return Result;

⚫

Put_Line("Union: [" & (-(Union(s1, s2))) & "],");

end To_Set;

⚫

Put_Line("Difference: [" & (-(Difference(s1, s2))) & "],");

⚫

Put_Line("Symmetric Diff: [" & (-(s1 xor s2)) & "],");

function Image(S: Set) return String is

⚫

Put_Line("Subset: " & Boolean'Image(s1.Is_Subset(s2))

C: Character;

T: ~~Set~~ := S;

& ", Equal: " & Boolean'Image(s1 = s2) & ".");

⚫

end loop;

begin

end set_demo;

if T.Is_Empty then

return "";

else

C:= T.First_Element;

T.Delete_First;

return C & Image(T);

end if;

end Image;

function Image(C: Ada.Containers.Count_Type) return String renames

Ada.Containers.Count_Type'Image;

S1, S2: Set;

begin -- main program

⚫

loop

S1 := To_Set(Ada.Text_IO.Get_Line);

⚫

exit when S1 = ~~To_Set(~~"~~quit~~!");

S2 := To_Set(Ada.Text_IO.Get_Line);

IO.Put_Line("Sets [" & Image(S1) & "], [" & Image(S2) & "] of size"

⚫

& ~~Image(~~S1.Length) & " and" & ~~Image(S2~~.Length) & ".");

⚫

~~IO.~~Put_Line("Intersection: [" & ~~Image~~(Intersection(S1, S2)) & "],");

⚫

~~IO.~~Put_Line("Union: [" & ~~Image~~(Union(S1, S2)) & "],");

⚫

~~IO.~~Put_Line("Difference: [" & ~~Image~~(Difference(S1, S2)) & "],");

⚫

~~IO.~~Put_Line("Symmetric Diff: [" & ~~Image~~(S1 xor S2) & "],");

⚫

~~IO.~~Put_Line("Subset: " & Boolean'Image(S1.Is_Subset(S2))

& ", Equal: " & Boolean'Image(S1 = S2) & ".");

end loop;

end Set_Demo;

</lang>