/eight.adb
http://github.com/rtyler/euler-ada · Ada · 57 lines · 45 code · 7 blank · 5 comment · 3 complexity · b3c40c2522d1bd2f2ac88023d932e5ca MD5 · raw file
- --
- -- Project Euler problem #8
- --
- -- Find the greatest product of five consecutive digits in the 1000-digit
- -- number.
- with Ada.Text_IO;
- use Ada.Text_IO;
- procedure Eight is
- Source : constant String := "73167176531330624919225119674426574742355349194934" &
- "96983520312774506326239578318016984801869478851843" &
- "85861560789112949495459501737958331952853208805511" &
- "12540698747158523863050715693290963295227443043557" &
- "66896648950445244523161731856403098711121722383113" &
- "62229893423380308135336276614282806444486645238749" &
- "30358907296290491560440772390713810515859307960866" &
- "70172427121883998797908792274921901699720888093776" &
- "65727333001053367881220235421809751254540594752243" &
- "52584907711670556013604839586446706324415722155397" &
- "53697817977846174064955149290862569321978468622482" &
- "83972241375657056057490261407972968652414535100474" &
- "82166370484403199890008895243450658541227588666881" &
- "16427171479924442928230863465674813919123162824586" &
- "17866458359124566529476545682848912883142607690042" &
- "24219022671055626321111109370544217506941658960408" &
- "07198403850962455444362981230987879927244284909188" &
- "84580156166097919133875499200524063689912560717606" &
- "05886116467109405077541002256983155200055935729725" &
- "71636269561882670428252483600823257530420752963450";
- function Digits_Product (Input : in String) return Natural is
- Result : Natural := 1;
- begin
- for Item in Input'Range loop
- Result := (Result * Natural'Value (Input (Item .. Item)));
- end loop;
- return Result;
- end Digits_Product;
- Highest : Natural := 0;
- begin
- for Index in 1 .. (Source'Length - 5) loop
- declare
- Sub : constant String := Source (Index .. Index + 4);
- Product : constant Natural := Digits_Product (Sub);
- begin
- if Product > Highest then
- Highest := Product;
- end if;
- end;
- end loop;
- Put_Line ("> Highest product:" & Natural'Image (Highest));
- end Eight;