Statistics

Problem Statement for "SpamChecker"

Problem Statement

Wolf Sothe was troubled with e-mail spam every day, so he decided to make his own spam filter.

Sothe's approach starts by looking at each line of the e-mail separately and classifying it either as good or bad. The more bad lines an e-mail contains, the more likely it is a spam.

Sothe already implemented the above part, and you are given its output as a String judgeLog. The characters of judgeLog correspond to the lines of an e-mail, in order. The character 'o' represents a good line and the character 'x' represents a bad line. For example, judgeLog="oxooo" corresponds to an e-mail with 5 lines. The second line of this e-mail is bad and the other four lines are good.

Sothe now came up with an algorithm to decide whether an e-mail is spam. Pseudocode of the algorithm is shown below. 

At the beginning, set the score of the e-mail to 0.
For each line of the e-mail, in order:
    If the line is good, increase the score by G.
    If the line is bad, decrease the score by B.
    If the score is now negative (i.e., smaller than 0):
        Classify the e-mail as "SPAM" and terminate.
If the score was never negative:
    Classify the e-mail as "NOT SPAM" and terminate.


In the pseudocode, G and B are positive integers. You are given their values as ints good and bad.

Return "SPAM" (quotes for clarity) if the e-mail described by judgeLog is a spam, and "NOT SPAM" otherwise.

Definition

Class:
SpamChecker
Method:
spamCheck
Parameters:
String, int, int
Returns:
String
Method signature:
String spamCheck(String judgeLog, int good, int bad)
(be sure your method is public)

Constraints

  • judgeLog will contain between 1 and 50 characters, inclusive.
  • Each character in judgeLog will be 'o' or 'x'.
  • good will be between 1 and 1000, inclusive.
  • bad will be between 1 and 1000, inclusive.

Examples

  1. "ooooxxxo"

    2

    3

    Returns: "SPAM"

    After the 7th line of this e-mail the score is 2+2+2+2-3-3-3 = -1. Hence, at that moment the e-mail gets classified as spam.

  2. "ooooxxxo"

    3

    4

    Returns: "NOT SPAM"

    In this case, the score of the e-mail will never be negative, so it gets classified as not spam. Note that after 7 lines of this e-mail the score is 0, but that does not make it a spam.

  3. "xooooooooooooooooooooooooooo"

    1000

    1

    Returns: "SPAM"

  4. "oxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

    1000

    1

    Returns: "NOT SPAM"

  5. "ooxoxoxooxoxxoxoxooxoxoxoxxoxx"

    15

    17

    Returns: "SPAM"

  6. "oooxoxoxoxoxoxooxooxoxooxo"

    16

    18

    Returns: "NOT SPAM"

  7. "o"

    1

    1

    Returns: "NOT SPAM"

  8. "x"

    1

    1

    Returns: "SPAM"

  9. "ox"

    1

    1

    Returns: "NOT SPAM"

  10. "xo"

    1

    1

    Returns: "SPAM"

  11. "oo"

    1

    1

    Returns: "NOT SPAM"

  12. "xx"

    1

    1

    Returns: "SPAM"

  13. "oxoxxxxxoooooxoxxoxooxxxooxxoooxxo"

    945

    921

    Returns: "SPAM"

  14. "xxooxxxoooo"

    191

    492

    Returns: "SPAM"

  15. "xooxoxoxxxoxxxxoxooooooooxxoxxoooxoxxooxoxxoo"

    964

    657

    Returns: "SPAM"

  16. "oxxxxoxxxoox"

    565

    848

    Returns: "SPAM"

  17. "oxoxooooooxxoxxoooxxoxxooxoxxooxxoxoxooxooxxooxx"

    303

    788

    Returns: "SPAM"

  18. "oxxxxoxoxox"

    220

    387

    Returns: "SPAM"

  19. "o"

    683

    56

    Returns: "NOT SPAM"

  20. "oxxxoxxooxoxoxoxoxooxooox"

    874

    949

    Returns: "SPAM"

  21. "xxox"

    144

    645

    Returns: "SPAM"

  22. "oooooxoooooxoxxoooooooxoxoxxxooxxxoxxxxoo"

    80

    955

    Returns: "SPAM"

  23. "oox"

    433

    837

    Returns: "NOT SPAM"

  24. "oooxoxxoxooxxo"

    155

    529

    Returns: "SPAM"

  25. "oxxxxxooxooooxoxxooooxxxoxxoxoo"

    408

    750

    Returns: "SPAM"

  26. "xoooxxxooooxxoxxxooooxxxooxoxoxxooooo"

    842

    459

    Returns: "SPAM"

  27. "oooooxxoooxxoxooxxxooxxoxxooooxoxxooxoxoxxoxxoxoo"

    448

    25

    Returns: "NOT SPAM"

  28. "oxo"

    589

    793

    Returns: "SPAM"

  29. "oxxxo"

    507

    729

    Returns: "SPAM"

  30. "xxxxxxooooxoxxxxxxooooxxxoooxoooooxooxxxoo"

    642

    581

    Returns: "SPAM"

  31. "xoxxxxxxooooxoxxx"

    672

    605

    Returns: "SPAM"

  32. "oxooooxooxxxxxxxxxxooxo"

    649

    894

    Returns: "SPAM"

  33. "ooxxxxox"

    453

    610

    Returns: "SPAM"

  34. "xxxooxxxxooxxxooxxoxxoo"

    225

    778

    Returns: "SPAM"

  35. "xooxooooxoxxxooxxxxoxxoooxx"

    343

    762

    Returns: "SPAM"

  36. "ooxoxxooxooxxxxooxoxxxxxxxxxoxxoxxooxxxoooxoxoxx"

    494

    786

    Returns: "SPAM"

  37. "ooxoooxoxxxoxooooo"

    716

    577

    Returns: "NOT SPAM"

  38. "xoxxoxxxxxoxxoxoooooxxxooxxoxxxoooxxooooooooxooooo"

    596

    354

    Returns: "SPAM"

  39. "oxxxxoxoxxooxoooxxoxxoxoooxxoxxoxxxoxxoxxoxxxxox"

    26

    644

    Returns: "SPAM"

  40. "ooooxo"

    357

    740

    Returns: "NOT SPAM"

  41. "xoooxoxoxxxxxoxooxxoxooo"

    912

    58

    Returns: "SPAM"

  42. "oxoxooxxxxoxxooxxoo"

    438

    614

    Returns: "SPAM"

  43. "xo"

    3

    1

    Returns: "SPAM"

  44. "x"

    1

    5

    Returns: "SPAM"

  45. "xoo"

    10

    10

    Returns: "SPAM"

  46. "oxxoooo"

    4

    7

    Returns: "SPAM"

  47. "xoooo"

    2

    1

    Returns: "SPAM"

  48. "xoooo"

    10

    3

    Returns: "SPAM"

  49. "ox"

    20

    30

    Returns: "SPAM"

  50. "xxoo"

    2

    2

    Returns: "SPAM"

  51. "xxxoooo"

    2

    2

    Returns: "SPAM"

  52. "xo"

    100

    10

    Returns: "SPAM"

  53. "xooooo"

    100

    1

    Returns: "SPAM"

  54. "xoooo"

    1000

    1

    Returns: "SPAM"

  55. "xoooooooooo"

    1

    1

    Returns: "SPAM"

  56. "ox"

    5

    5

    Returns: "NOT SPAM"

  57. "ox"

    2

    5

    Returns: "SPAM"

  58. "ox"

    2

    3

    Returns: "SPAM"

  59. "ox"

    2

    2

    Returns: "NOT SPAM"

  60. "xoooo"

    1

    1

    Returns: "SPAM"

  61. "oxxxooooo"

    1

    1

    Returns: "SPAM"

  62. "xo"

    2

    1

    Returns: "SPAM"

  63. "xo"

    10

    9

    Returns: "SPAM"

  64. "ooooooooooooooooooooooooooooooooooooooooooooooooox"

    1

    1000

    Returns: "SPAM"

  65. "xxoooo"

    5

    1

    Returns: "SPAM"

  66. "xoo"

    30

    5

    Returns: "SPAM"

  67. "oooxxx"

    1

    1

    Returns: "NOT SPAM"

  68. "x"

    2

    3

    Returns: "SPAM"

  69. "ox"

    2

    1

    Returns: "NOT SPAM"

  70. "ox"

    1

    2

    Returns: "SPAM"

  71. "ooxxx"

    1

    1

    Returns: "SPAM"

  72. "xo"

    5

    1

    Returns: "SPAM"

  73. "x"

    100

    100

    Returns: "SPAM"

  74. "x"

    5

    10

    Returns: "SPAM"

  75. "xoo"

    1

    1

    Returns: "SPAM"

  76. "xxx"

    2

    2

    Returns: "SPAM"

  77. "ox"

    3

    3

    Returns: "NOT SPAM"

  78. "ox"

    5

    10

    Returns: "SPAM"

  79. "x"

    5

    7

    Returns: "SPAM"

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