with Ada.Characters.Handling;
use Ada.Characters.Handling;
package Abc is
type Block_Faces is array(1..2) of Character;
type Block_List is array(positive range <>) of Block_Faces;
function Can_Make_Word(W: String; Blocks: Block_List) return Boolean;
end Abc;
package body Abc is
function Can_Make_Word(W: String; Blocks: Block_List) return Boolean is
Used : array(Blocks'Range) of Boolean := (Others => False);
subtype wIndex is Integer range W'First..W'Last;
wPos : wIndex;
begin
if W'Length = 0 then
return True;
end if;
wPos := W'First;
while True loop
declare
C : Character := To_Upper(W(wPos));
X : constant wIndex := wPos;
begin
for I in Blocks'Range loop
if (not Used(I)) then
if C = To_Upper(Blocks(I)(1)) or C = To_Upper(Blocks(I)(2)) then
Used(I) := True;
if wPos = W'Last then
return True;
end if;
wPos := wIndex'Succ(wPos);
exit;
end if;
end if;
end loop;
if X = wPos then
return False;
end if;
end;
end loop;
return False;
end Can_Make_Word;
end Abc;
with Ada.Text_IO, Ada.Strings.Unbounded, Abc;
use Ada.Text_IO, Ada.Strings.Unbounded, Abc;
procedure Abc_Problem is
Blocks : Block_List := (
('B','O'), ('X','K'), ('D','Q'), ('C','P')
, ('N','A'), ('G','T'), ('R','E'), ('T','G')
, ('Q','D'), ('F','S'), ('J','W'), ('H','U')
, ('V','I'), ('A','N'), ('O','B'), ('E','R')
, ('F','S'), ('L','Y'), ('P','C'), ('Z','M')
);
function "+" (S : String) return Unbounded_String renames To_Unbounded_String;
words : array(positive range <>) of Unbounded_String := (
+"A"
, +"BARK"
, +"BOOK"
, +"TREAT"
, +"COMMON"
, +"SQUAD"
, +"CONFUSE"
-- Border cases:
-- , +"CONFUSE2"
-- , +""
);
begin
for I in words'Range loop
Put_Line ( To_String(words(I)) & ": " & Boolean'Image(Can_Make_Word(To_String(words(I)),Blocks)) );
end loop;
end Abc_Problem;