Valid Parentheses - Merge pull request #543 from iKostanOrg/master

kyu_7/README.md

@@ -15,39 +15,40 @@ rank - the harder the kata the faster you advance.
 
 ### List of Completed Kata (Python 3)
 <!-- markdownlint-disable MD013 -->
-| No. | Puzzle/Kata Name                                                                                              |                                                                                                                Solution / GitHub Link |
-|-----|:--------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------:|
-| 1   | [Always perfect](https://www.codewars.com/kata/55f3facb78a9fd5b26000036)                                      |                                                      [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/always_perfect) |
-| 2   | [Beginner Series #3 Sum of Numbers](https://www.codewars.com/kata/55f2b110f61eb01779000053)                   |                                      [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/beginner_series_sum_of_numbers) |
-| 2   | [Coloured Triangles](https://www.codewars.com/kata/5a25ac6ac5e284cfbe000111)                                  |                                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/coloured_triangles) |
-| 3   | [Disemvowel Trolls](https://www.codewars.com/kata/52fba66badcd10859f00097e)                                   |                                                   [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/disemvowel_trolls) |
-| 4   | [Factorial](https://www.codewars.com/kata/54ff0d1f355cfd20e60001fc)                                           |                                                           [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/factorial) |
-| 5   | [Computer problem series #1](https://www.codewars.com/kata/5d49c93d089c6e000ff8428c)                          |                                            [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/fill_the_hard_disk_drive) |
-| 6   | [Fun with lists: length](https://www.codewars.com/kata/581e476d5f59408553000a4b)                              |                                               [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/fun_with_lists_length) |
-| 7   | [Jaden Casing Strings](https://www.codewars.com/kata/5390bac347d09b7da40006f6)                                |                                                [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/jaden_casing_strings) |
-| 8   | [Make Class](https://www.codewars.com/kata/5d774cfde98179002a7cb3c8)                                          |                                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/make_class) |
-| 9   | [Maximum Multiple](https://www.codewars.com/kata/5aba780a6a176b029800041c)                                    |                                                    [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/maximum_multiple) |
-| 10  | [Password validator](https://www.codewars.com/kata/56a921fa8c5167d8e7000053)                                  |                                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/password_validator) |
-| 11  | [Powers of 3](https://www.codewars.com/kata/57be674b93687de78c0001d9)                                         |                                                         [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/powers_of_3) |
-| 12  | [Pull your words together, man!](https://www.codewars.com/kata/59ad7d2e07157af687000070)                      |                                        [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/pull_your_words_together_man) |
-| 13  | [The museum of incredible dull things](https://www.codewars.com/kata/563cf89eb4747c5fb100001b)                |                                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/remove_the_minimum) |
-| 14  | [Share price](https://www.codewars.com/kata/5603a4dd3d96ef798f000068)                                         |                                                        [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/share_prices) |
-| 15  | [Significant Figures Challenge](https://www.codewars.com/kata/5d9fe0ace0aad7001290acb7)                       |                                                 [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/significant_figures) |
-| 16  | [Simple Fun #152: Invite More Women](https://www.codewars.com/kata/58acfe4ae0201e1708000075)                  |                                                      [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/simple_fun_152) |
-| 17  | [Sort Out The Men From Boys](https://www.codewars.com/kata/5af15a37de4c7f223e00012d)                          |                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sort_out_the_men_from_boys) |
-| 18  | [Substituting Variables Into Strings: Padded Numbers](https://www.codewars.com/kata/51c89385ee245d7ddf000001) |                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/substituting_variables_into_strings_padded_numbers) |
-| 19  | [Sum of powers of 2](https://www.codewars.com/kata/5d9f95424a336600278a9632)                                  |                                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_powers_of_2) |
-| 20  | [Sum of Triangular Numbers](https://www.codewars.com/kata/580878d5d27b84b64c000b51)                           |                                           [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_triangular_numbers) |
-| 21  | [Sum of two lowest positive integers](https://www.codewars.com/kata/558fc85d8fd1938afb000014)                 |                                               [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_two_lowest_int) |
-| 22  | [The First Non Repeated Character In A String](https://www.codewars.com/kata/570f6436b29c708a32000826)        |                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/the_first_non_repeated_character_in_string) |
-| 23  | [V A P O R C O D E](https://www.codewars.com/kata/5966eeb31b229e44eb00007a)                                   |                                                           [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/vaporcode) |
-| 24  | [You're a square](https://www.codewars.com/kata/54c27a33fb7da0db0100040e)                                     |                                                      [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/you_are_square) |
-| 25  | [Find the longest gap!](https://www.codewars.com/kata/55b86beb1417eab500000051)                               |                                                [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/find_the_longest_gap) |
-| 26  | [Simple Fun #74: Growing Plant](https://www.codewars.com/kata/58941fec8afa3618c9000184)                       |                                                       [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/growing_plant) |
-| 27  | [Basic Math (Add or Subtract)](https://www.codewars.com/kata/5809b62808ad92e31b000031)                        |                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/basic_math_add_or_subtract) |
-| 28  | [Sum of odd numbers](https://www.codewars.com/kata/55fd2d567d94ac3bc9000064)                                  |                                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_odd_numbers) |
-| 29  | [Help Bob count letters and digits](https://www.codewars.com/kata/5738f5ea9545204cec000155)                   |                                   [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/help_bob_count_letters_and_digits) |
-| 30  | [Make Class](https://www.codewars.com/kata/5d774cfde98179002a7cb3c8)                                          |                                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/make_class) |
-| 30  | [Easy Line](https://www.codewars.com/kata/56e7d40129035aed6c000632)                                           |                                                           [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/easy_line) |
+| No. | Puzzle/Kata Name                                                                                                               |                                                                                               Solution / GitHub Link |
+|-----|:-------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------:|
+| 1   | [Always perfect](https://www.codewars.com/kata/55f3facb78a9fd5b26000036)                                                       |                                     [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/always_perfect) |
+| 2   | [Beginner Series #3 Sum of Numbers](https://www.codewars.com/kata/55f2b110f61eb01779000053)                                    |                     [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/beginner_series_sum_of_numbers) |
+| 2   | [Coloured Triangles](https://www.codewars.com/kata/5a25ac6ac5e284cfbe000111)                                                   |                                 [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/coloured_triangles) |
+| 3   | [Disemvowel Trolls](https://www.codewars.com/kata/52fba66badcd10859f00097e)                                                    |                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/disemvowel_trolls) |
+| 4   | [Factorial](https://www.codewars.com/kata/54ff0d1f355cfd20e60001fc)                                                            |                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/factorial) |
+| 5   | [Computer problem series #1](https://www.codewars.com/kata/5d49c93d089c6e000ff8428c)                                           |                           [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/fill_the_hard_disk_drive) |
+| 6   | [Fun with lists: length](https://www.codewars.com/kata/581e476d5f59408553000a4b)                                               |                              [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/fun_with_lists_length) |
+| 7   | [Jaden Casing Strings](https://www.codewars.com/kata/5390bac347d09b7da40006f6)                                                 |                               [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/jaden_casing_strings) |
+| 8   | [Make Class](https://www.codewars.com/kata/5d774cfde98179002a7cb3c8)                                                           |                                         [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/make_class) |
+| 9   | [Maximum Multiple](https://www.codewars.com/kata/5aba780a6a176b029800041c)                                                     |                                   [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/maximum_multiple) |
+| 10  | [Password validator](https://www.codewars.com/kata/56a921fa8c5167d8e7000053)                                                   |                                 [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/password_validator) |
+| 11  | [Powers of 3](https://www.codewars.com/kata/57be674b93687de78c0001d9)                                                          |                                        [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/powers_of_3) |
+| 12  | [Pull your words together, man!](https://www.codewars.com/kata/59ad7d2e07157af687000070)                                       |                       [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/pull_your_words_together_man) |
+| 13  | [The museum of incredible dull things](https://www.codewars.com/kata/563cf89eb4747c5fb100001b)                                 |                                 [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/remove_the_minimum) |
+| 14  | [Share price](https://www.codewars.com/kata/5603a4dd3d96ef798f000068)                                                          |                                       [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/share_prices) |
+| 15  | [Significant Figures Challenge](https://www.codewars.com/kata/5d9fe0ace0aad7001290acb7)                                        |                                [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/significant_figures) |
+| 16  | [Simple Fun #152: Invite More Women](https://www.codewars.com/kata/58acfe4ae0201e1708000075)                                   |                                     [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/simple_fun_152) |
+| 17  | [Sort Out The Men From Boys](https://www.codewars.com/kata/5af15a37de4c7f223e00012d)                                           |                         [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sort_out_the_men_from_boys) |
+| 18  | [Substituting Variables Into Strings: Padded Numbers](https://www.codewars.com/kata/51c89385ee245d7ddf000001)                  | [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/substituting_variables_into_strings_padded_numbers) |
+| 19  | [Sum of powers of 2](https://www.codewars.com/kata/5d9f95424a336600278a9632)                                                   |                                 [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_powers_of_2) |
+| 20  | [Sum of Triangular Numbers](https://www.codewars.com/kata/580878d5d27b84b64c000b51)                                            |                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_triangular_numbers) |
+| 21  | [Sum of two lowest positive integers](https://www.codewars.com/kata/558fc85d8fd1938afb000014)                                  |                              [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_two_lowest_int) |
+| 22  | [The First Non Repeated Character In A String](https://www.codewars.com/kata/570f6436b29c708a32000826)                         |         [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/the_first_non_repeated_character_in_string) |
+| 23  | [V A P O R C O D E](https://www.codewars.com/kata/5966eeb31b229e44eb00007a)                                                    |                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/vaporcode) |
+| 24  | [You're a square](https://www.codewars.com/kata/54c27a33fb7da0db0100040e)                                                      |                                     [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/you_are_square) |
+| 25  | [Find the longest gap!](https://www.codewars.com/kata/55b86beb1417eab500000051)                                                |                               [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/find_the_longest_gap) |
+| 26  | [Simple Fun #74: Growing Plant](https://www.codewars.com/kata/58941fec8afa3618c9000184)                                        |                                      [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/growing_plant) |
+| 27  | [Basic Math (Add or Subtract)](https://www.codewars.com/kata/5809b62808ad92e31b000031)                                         |                         [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/basic_math_add_or_subtract) |
+| 28  | [Sum of odd numbers](https://www.codewars.com/kata/55fd2d567d94ac3bc9000064)                                                   |                                 [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/sum_of_odd_numbers) |
+| 29  | [Help Bob count letters and digits](https://www.codewars.com/kata/5738f5ea9545204cec000155)                                    |                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/help_bob_count_letters_and_digits) |
+| 30  | [Make Class](https://www.codewars.com/kata/5d774cfde98179002a7cb3c8)                                                           |                                         [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/make_class) |
+| 30  | [Easy Line](https://www.codewars.com/kata/56e7d40129035aed6c000632)                                                            |                                          [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/easy_line) |
+| 31  | [Valid Parentheses](https://www.codewars.com/kata/6411b91a5e71b915d237332d)                                                    |                                  [Solution](https://github.com/ikostan/codewars/tree/master/kyu_7/valid_parentheses) |
 <!-- markdownlint-enable MD013 -->
 [Source](https://www.codewars.com/about)

kyu_7/valid_parentheses/README.md

@@ -0,0 +1,26 @@
+# Valid Parentheses
+
+Write a function that takes a string of parentheses, and determines
+if the order of the parentheses is valid. The function should return
+true if the string is valid, and false if it's invalid.
+
+Examples:
+```bash
+"()"              =>  true
+")(()))"          =>  false
+"("               =>  false
+"(())((()())())"  =>  true
+```
+
+Constraints
+
+```bash 0 <= length of input <= 100```
+
+- All inputs will be strings, consisting only of characters ( and ).
+- Empty strings are considered balanced (and therefore valid), and will be tested.
+- For languages with mutable strings, the inputs should not be mutated.
+
+*Tip:* If you are trying to figure out why a string of parentheses is invalid,
+paste the parentheses into the code editor, and let the code highlighting show you!
+
+[Source](https://www.codewars.com/kata/6411b91a5e71b915d237332d)

kyu_7/valid_parentheses/solution.py

@@ -0,0 +1,52 @@
+"""
+Solution for -> Valid Parentheses
+Created by Egor Kostan.
+GitHub: https://github.com/ikostan
+"""
+
+def valid_parentheses(paren_str: str) -> bool:
+    """
+    A function that takes a string of parentheses, and determines
+    if the order of the parentheses is valid. The function should
+    return true if the string is valid, and false if it's invalid.
+    :param paren_str: str
+    :return: bool
+    """
+    print(paren_str)
+
+    # Should return True for empty strings
+    if not paren_str:
+        return True
+
+    # Fail if starts from closing bracket
+    if paren_str[0] == ')':
+        return False
+
+    # A number of closing and opening
+    # brackets should be equal
+    if paren_str.count('(') != paren_str.count(')'):
+        return False
+
+    while paren_str:
+        # Fail if starts from closing bracket
+        if paren_str[0] == ')':
+            return False
+        # Find matching pair and remove them from the string
+        for i in range(1, len(paren_str)):
+            if paren_str[i] == ')':
+                paren_str = update_str(paren_str, i)
+                break
+
+    return True
+
+
+def update_str(paren_str: str, i: int) -> str:
+    """
+    Update string:
+    1. remove first char.
+    2. remove matching char/bracket.
+    :param paren_str: str
+    :param i: int
+    :return: str
+    """
+    return ''.join(paren_str[indx] for indx, char in enumerate(paren_str) if indx not in [0, i])