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Problem Statement for "Alpha"

Problem Statement

Limak is a little bear who wants to learn the English alphabet. He tries to say the whole alphabet from 'a' to 'z'. Your job is to stop him when he makes a mistake. Can you check how many first letters he said correctly?

You are given a String s that consists of lowercase English letters. Find how many first characters match the beginning of the English alphabet. The English alphabet looks as follows: abcdefghijklmnopqrstuvwxyz.

Definition

Class:
Alpha
Method:
maxPref
Parameters:
String
Returns:
int
Method signature:
int maxPref(String s)
(be sure your method is public)

Constraints

  • The number of characters in s will be between 1 and 26, inclusive.
  • Each character in s will be a lowercase English character ('a' - 'z').

Examples

  1. "abctyf"

    Returns: 3

    The first three characters match: a, b, c.

  2. "abcdefghijklmnopqrstuvwxyz"

    Returns: 26

    All 26 characters match the English alphabet exactly.

  3. "zyx"

    Returns: 0

  4. "abcdegfhijk"

    Returns: 5

    Characters 'f' and 'g' are swapped, so we only accept first five characters (abcde).

  5. "ba"

    Returns: 0

  6. "aabc"

    Returns: 1

  7. "abcdefghijklmno"

    Returns: 15

  8. "a"

    Returns: 1

  9. "b"

    Returns: 0

  10. "z"

    Returns: 0

  11. "aa"

    Returns: 1

  12. "bb"

    Returns: 0

  13. "edcba"

    Returns: 0

  14. "abcdefhij"

    Returns: 6

  15. "abcdefhijg"

    Returns: 6

  16. "cabd"

    Returns: 0

  17. "ab"

    Returns: 2

  18. "abb"

    Returns: 2

  19. "abc"

    Returns: 3

  20. "abcm"

    Returns: 3

  21. "abcd"

    Returns: 4

  22. "abcdz"

    Returns: 4

  23. "abcde"

    Returns: 5

  24. "abcdeb"

    Returns: 5

  25. "abcdef"

    Returns: 6

  26. "abcdefm"

    Returns: 6

  27. "abcdefg"

    Returns: 7

  28. "abcdefgw"

    Returns: 7

  29. "abcdefgh"

    Returns: 8

  30. "abcdefghe"

    Returns: 8

  31. "abcdefghi"

    Returns: 9

  32. "abcdefghiy"

    Returns: 9

  33. "abcdefghij"

    Returns: 10

  34. "abcdefghijy"

    Returns: 10

  35. "abcdefghijk"

    Returns: 11

  36. "abcdefghijkd"

    Returns: 11

  37. "abcdefghijkl"

    Returns: 12

  38. "abcdefghijkli"

    Returns: 12

  39. "abcdefghijklm"

    Returns: 13

  40. "abcdefghijklma"

    Returns: 13

  41. "abcdefghijklmn"

    Returns: 14

  42. "abcdefghijklmnd"

    Returns: 14

  43. "abcdefghijklmno"

    Returns: 15

  44. "abcdefghijklmnot"

    Returns: 15

  45. "abcdefghijklmnop"

    Returns: 16

  46. "abcdefghijklmnopl"

    Returns: 16

  47. "abcdefghijklmnopq"

    Returns: 17

  48. "abcdefghijklmnopqc"

    Returns: 17

  49. "abcdefghijklmnopqr"

    Returns: 18

  50. "abcdefghijklmnopqro"

    Returns: 18

  51. "abcdefghijklmnopqrs"

    Returns: 19

  52. "abcdefghijklmnopqrsu"

    Returns: 19

  53. "abcdefghijklmnopqrst"

    Returns: 20

  54. "abcdefghijklmnopqrste"

    Returns: 20

  55. "abcdefghijklmnopqrstu"

    Returns: 21

  56. "abcdefghijklmnopqrstug"

    Returns: 21

  57. "abcdefghijklmnopqrstuv"

    Returns: 22

  58. "abcdefghijklmnopqrstuvm"

    Returns: 22

  59. "abcdefghijklmnopqrstuvw"

    Returns: 23

  60. "abcdefghijklmnopqrstuvwd"

    Returns: 23

  61. "abcdefghijklmnopqrstuvwx"

    Returns: 24

  62. "abcdefghijklmnopqrstuvwxb"

    Returns: 24

  63. "abcdefghijklmnopqrstuvwxy"

    Returns: 25

  64. "abcdefghijklmnopqrstuvwxyy"

    Returns: 25

  65. "bcdefghijklmnopqrstuvwxyz"

    Returns: 0

  66. "zyxwvutsrqponmlkjihgfedcba"

    Returns: 0

  67. "owcmqodugmvopquucnalghassv"

    Returns: 0

  68. "aaabcskfnao"

    Returns: 1

  69. "xb"

    Returns: 0

  70. "abcdg"

    Returns: 4

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