-- Reads in strings, counts the number of distinct vowels
-- For strings with 0..3 vowels, stores the head (2 chars)
-- For strings with 4..6 vowels, stores the tail (3 chars)
-- Prints all heads, followed by all tails
-- Example input:
-- abcde
-- aeiou
-- bbb
-- Example output:
-- ab
-- bb
-- iou
pragma Assertion_Policy (Check); -- Turn on Dynamic_Predicate checking
with ada.text_io; use ada.text_io;
procedure vowels_variations is
type Distinct_Vowel_Count is range 0 .. 6;
-- Count number of distinct vowels in s
-- A second version to consider
function number_distinct_vowels(s: String) return Distinct_Vowel_Count is
check: array(Character) of Boolean := (others => false);
begin
for c of s loop
check(c) := true;
end loop;
return (if check('a') then 1 else 0)
+ (if check('e') then 1 else 0)
+ (if check('i') then 1 else 0)
+ (if check('o') then 1 else 0)
+ (if check('u') then 1 else 0)
+ (if check('y') then 1 else 0);
-- Another way to calculate the answer
-- for b of check loop
-- if b then
-- ans := ans + 1;
-- end if;
-- end loop;
-- return ans;
-- Yet Another way to calculate the answer
-- subtype vowels is Character
-- with static_predicate => vowels in 'a'|'e'|'i'|'o'|'u'|'y';
-- for v in vowels loop
-- if check(v) then
-- ans := ans + 1;
-- end if;
-- end loop;
-- return ans;
end number_distinct_vowels;
-- Count number of distinct vowels in s
-- A third version to consider
function number_distinct_vowels2(s: String) return Distinct_Vowel_Count is
type vowels is (a, e, i, o, u, y, not_a_vowel);
function char2vowel(c: Character) return vowels is
(case c is when 'a' => a, when 'e' => e, when 'i' => i, when 'o' => o,
when 'u' => u, when 'y' => y, when others => not_a_vowel);
subtype Binary_Distinct_Vowel_COunt is Distinct_Vowel_Count range 0 .. 1;
function bool2BDVC(b: Boolean) return Binary_Distinct_Vowel_COunt is
(if b then 1 else 0);
check: array(vowels) of Boolean;
ans: Distinct_Vowel_Count := 0;
begin
for c of s loop
check(char2vowel(c)) := true;
end loop;
for v in vowels loop
ans := ans + bool2BDVC(check(v));
-- ans := ans + Boolean'Pos(check(v));
-- The above works since False is at position 0, True at position 1!
-- Not necessarily a good idea!
end loop;
return ans;
end number_distinct_vowels2;
subtype Long_String is String with
Dynamic_Predicate => Long_String'length >= 3;
-- Predicate_Failure => raise Constraint_Error with "String too short!";
-- Unfortunately Predicate_Failure is not yet implemented
HEAD_LENGTH: Constant := 2;
TAIL_LENGTH: COnstant := 3;
MAX_NUM_STRINGS: Constant := 100;
type String_Count is range 0 .. MAX_NUM_STRINGS;
subtype String_Index is String_Count range 1 .. String_Count'last;
package String_Count_IO is new Ada.Text_IO.Integer_IO(String_Count);
use String_Count_IO;
type Heads_Array is array(String_Index) of String(1 .. HEAD_LENGTH);
type Tails_Array is array(String_Index) of String(1 .. TAIL_LENGTH);
procedure process_one_string(
s: Long_String;
num_heads: in out String_Count;
num_tails: in out String_Count;
heads: in out Heads_Array;
tails: in out Tails_Array)
is
HEAD_END: Constant Natural := s'first + HEAD_LENGTH - 1;
TAIL_START: Constant Natural := s'last - TAIL_LENGTH + s'first;
subtype Few_Vowels is Distinct_Vowel_Count range 0 .. 3;
begin
if number_distinct_vowels(s) in Few_Vowels then
num_heads := num_heads + 1;
heads(num_heads) := s(s'first .. HEAD_END);
else
num_tails := num_tails + 1;
tails(num_tails) := s(TAIL_START .. s'last);
end if;
end process_one_string;
-- Slightly shorter version
procedure get_and_process_all_strings(
num_heads: out String_Count;
num_tails: out String_Count;
heads: out Heads_Array;
tails: out Tails_Array)
is
begin
num_heads := 0;
num_tails := 0;
while not end_of_file loop
process_one_string(get_line, num_heads, num_tails, heads, tails);
end loop;
end get_and_process_all_strings;
procedure put(num_heads: String_Count; num_tails: String_Count;
heads: Heads_Array; tails: Tails_Array)
is
begin
for i in 1 .. num_heads loop
put_line(heads(i));
end loop;
for i in 1 .. num_tails loop
put_line(tails(i));
end loop;
end put;
heads: Heads_Array; -- Array for heads
tails: Tails_Array; -- Array for tails
num_heads,
num_tails: String_Count := 0; -- Number of heads and tails
begin
get_and_process_all_strings(num_heads, num_tails, heads, tails);
put(num_heads, num_tails, heads, tails);
put(num_heads); -- Where is this put from?
put(num_tails);
end vowels_variations;