Code challenge 13

Author: maddieamie

Diff for: README.md

@@ -20,4 +20,6 @@
 
 [PseudoQueue](python/pseudo_queue/README.md)
 
-[Animal Shelter](python/stack_queue_animal_shelter/README.md)
+[Animal Shelter](python/stack_queue_animal_shelter/README.md)
+
+[Stack Queue Brackets](python/stack_queue_brackets/README.md)

Diff for: python/stack_queue_brackets/README.md

@@ -0,0 +1,43 @@
+# Stack + Queue Brackets
+<!-- Description of the challenge -->
+Write a function called validate brackets
+**Arguments**: string
+**Return**: boolean
+ - representing whether or not the brackets in the string are balanced
+
+_There are 3 types of brackets:_
+
+- Round Brackets : ()
+- Square Brackets : []
+- Curly Brackets : {}
+
+- _This will use code from [Stack](python/stacks_and_queues/stack.py)_
+
+## Approach & Efficiency
+<!-- What approach did you take? Why? What is the Big O space/time for this approach? -->
+
+I enumerated the string characters so that the node being pushed to a stack would contain the data and the index of the character. Essentially, the logic is to push to the stack for an opening bracket and then pop for a closing bracket. Then, I used conditional logic to make sure that the index of the closing bracket was not before the opening bracket, the stack is not empty when trying to pop from it upon coming across a closing bracket, and making sure that the brackets match the appropriate bracket type. 
+
+
+**Time: O(1)**
+-  because only deals with one node at a time for all of these methods, since the nodes being accessed are only at the top of the stack.
+- However, this method overall may use also 0(n^2), because I am calling on two iterative methods of a dictionary to access the keys and values. 
+
+**Space: O(n)**
+- For the space of the character string list and the space of the Stack individually, O(2n) for both of those combined in memory. 
+
+## Solution
+<!-- Show how to run your code, and examples of it in action -->
+
+Terminal command for general main module: python3 -m stack_queue_brackets.stack_queue_brackets
+
+Terminal command for testing in pytest: python3 -m pytest stack_queue_brackets/
+
+![Test code in main module: collected 9 items
+stack_queue_brackets/stack_queue_brackets.py .....  100%, 9 passed in 0.01s](python/stack_queue_brackets/tests_passing.png)
+
+### Code Links
+
+[Stack Queue Brackets](python/stack_queue_brackets/stack_queue_brackets.py)
+
+[Tests of Stack Queue Brackets](python/stack_queue_brackets/test_stack_queue_brackets.py)

Diff for: python/stack_queue_brackets/__init__.py

@@ -0,0 +1,44 @@
+from stacks_and_queues.stack import Stack
+
+
+class Node3:
+    def __init__(self, data, index):
+        self.data = data
+        self.index = index
+        self.next = None
+
+
+def multi_bracket_validation(validation_input: str) -> bool:
+    stack = Stack()
+
+    pairs = {
+        '[': ']',
+        '{': '}',
+        '(': ')'
+    }
+
+    for index, char in enumerate(validation_input):
+        if char in pairs.keys():
+            new_node = Node3(char, index)
+            stack.push(new_node)
+        if char in pairs.values():
+            try:
+                top_data = stack.peek()
+                if index < top_data.index or not top_data:
+                    return False
+                elif char != pairs[top_data.data]:
+                    return False
+                else:
+                    stack.pop()
+            except Exception as e:
+                if str(e) == "Stack is empty":
+                    pass
+                else:
+                    raise e
+
+    return stack.is_empty()
+
+
+if __name__ == '__main__':
+
+    print(multi_bracket_validation("{}(){}]"))

Diff for: python/stack_queue_brackets/stack_queue_brackets.py

@@ -0,0 +1,65 @@
+import pytest
+from stack_queue_brackets.stack_queue_brackets import multi_bracket_validation
+
+
+# @pytest.mark.skip("TODO")
+def test_validates_two_square_brackets():
+    actual = multi_bracket_validation("[]")
+    expected = True
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_fails_two_square_brackets_flipped():
+    actual = multi_bracket_validation("][")
+    expected = False
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_validates_two_braces():
+    actual = multi_bracket_validation("{}")
+    expected = True
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_fails_two_braces_flipped():
+    actual = multi_bracket_validation("}{")
+    expected = False
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_validates_two_parentheses():
+    actual = multi_bracket_validation("()")
+    expected = True
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_fails_two_parentheses_flipped():
+    actual = multi_bracket_validation(")(")
+    expected = False
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_multi():
+    actual = multi_bracket_validation("{}(){}")
+    expected = True
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_nested():
+    actual = multi_bracket_validation("{([])}")
+    expected = True
+    assert actual == expected
+
+
+# @pytest.mark.skip("TODO")
+def test_mismatched():
+    actual = multi_bracket_validation("[}")
+    expected = False
+    assert actual == expected