GH-285: solve Leetcode 141, 283

collections/leetcode/data.yaml

@@ -69,6 +69,9 @@ problems:
 - name: 133
   languages: cpp
   level: medium
+- name: 141
+  languages: python
+  level: easy
 - name: 142
   languages: cpp
   level: medium
@@ -109,6 +112,9 @@ problems:
 - name: 278
   languages: cpp
   level: easy
+- name: 283
+  languages: python
+  level: easy
 - name: 347
   languages: cpp
   level: medium

problems/leetcode141/.gitignore

@@ -0,0 +1,3 @@
+solution
+*.dSYM
+python/main/__pycache__

problems/leetcode141/README.md

@@ -0,0 +1,10 @@
+# Leetcode Problem 
+
+## Usage
+
+Test program
+
+```
+# Run all tests
+python solution_test.py
+```

problems/leetcode141/data/1.in

@@ -0,0 +1,2 @@
+3,2,0,-4
+1

problems/leetcode141/data/1.out

@@ -0,0 +1 @@
+true

problems/leetcode141/data/2.in

@@ -0,0 +1,2 @@
+1,2
+0

problems/leetcode141/data/2.out

@@ -0,0 +1 @@
+true

problems/leetcode141/data/3.in

@@ -0,0 +1,2 @@
+1
+-1

problems/leetcode141/data/3.out

@@ -0,0 +1 @@
+false

problems/leetcode141/problem_infos.json

@@ -0,0 +1,9 @@
+{
+  "name": "141. Linked List Cycle",
+  "link": "https://leetcode.com/problems/linked-list-cycle/",
+  "tags": [
+    "Hash Table",
+    "Linked List",
+    "Two Pointers"
+  ]
+}

problems/leetcode141/python/main/solution.py

@@ -0,0 +1,17 @@
+from typing import Optional
+
+
+class ListNode:
+    def __init__(self, x):
+        self.val = x
+        self.next = None
+
+class Solution:
+    def hasCycle(self, head: Optional[ListNode]) -> bool:
+        slow = fast = head
+        while fast and fast.next:
+            slow = slow.next
+            fast = fast.next.next
+            if slow == fast:
+                return True
+        return False

problems/leetcode141/python/tests/solution_test.py

@@ -0,0 +1,62 @@
+import sys
+import unittest
+from os import listdir
+from os.path import abspath, dirname, join
+
+python_source = dirname(dirname(abspath(__file__)))
+sys.path.append(python_source)
+from main.solution import Solution
+
+test_data_directory = join(dirname(python_source), 'data')
+test_cases = set([data_file.split('.')[0] for data_file in listdir(test_data_directory)])
+
+class ListNode:
+    def __init__(self, x):
+        self.val = x
+        self.next = None
+
+def read_input(input_file):
+    with open(input_file, 'r') as f:
+        nums = [int(num) if num != '_' else None for num in f.readline().strip().strip('][').split(',') ]
+        val = int(f.readline().strip())
+        current = head = ListNode(0)
+        loop_node = None
+        for i, num in enumerate(nums):
+            current.next = ListNode(num)
+            current = current.next
+            if i == val:
+                loop_node = current
+        if loop_node is not None:
+            current.next = loop_node
+    return head.next, val
+
+def read_output(output_file):
+    with open(output_file, 'r') as f:
+        k = f.readline().strip()
+        k = False if k == 'false' else True
+        return k
+
+class TestSequenceMeta(type):
+    def __new__(mcs, name, bases, dict):
+
+        def gen_test(input_file, output_file):
+            def test(self):
+                solution = Solution()
+                head, val = read_input(input_file)
+                expected_k = read_output(output_file)
+                actual_k = solution.hasCycle(head)
+                self.assertEqual(actual_k, expected_k)
+            return test
+
+        for test_case in test_cases:
+            test_name = f'test_{test_case}'
+            input_file = join(test_data_directory, f'{test_case}.in')
+            output_file = join(test_data_directory, f'{test_case}.out')
+            dict[test_name] = gen_test(input_file, output_file)
+        return type.__new__(mcs, name, bases, dict)
+
+class TestSequence(unittest.TestCase, metaclass=TestSequenceMeta):
+    pass
+
+if __name__ == '__main__':
+    unittest.main()

problems/leetcode283/.gitignore

@@ -0,0 +1,3 @@
+solution
+*.dSYM
+python/main/__pycache__

problems/leetcode283/README.md

@@ -0,0 +1,10 @@
+# Leetcode Problem 
+
+## Usage
+
+Test program
+
+```
+# Run all tests
+python solution_test.py
+```

problems/leetcode283/data/1.in

@@ -0,0 +1 @@
+0,1,0,3,12

problems/leetcode283/data/1.out

@@ -0,0 +1 @@
+1,3,12,0,0

problems/leetcode283/data/2.in

@@ -0,0 +1 @@
+0

problems/leetcode283/data/2.out

@@ -0,0 +1 @@
+0

problems/leetcode283/problem_infos.json

@@ -0,0 +1,8 @@
+{
+  "name": "283. Move Zeroes",
+  "link": "https://leetcode.com/problems/move-zeroes/",
+  "tags": [
+    "Array",
+    "Two Pointers"
+  ]
+}

problems/leetcode283/python/main/solution.py

@@ -0,0 +1,15 @@
+from typing import List
+
+
+class Solution:
+    def moveZeroes(self, nums: List[int]) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        slow = 0
+        for fast in range(len(nums)):
+            if nums[fast] != 0 and nums[slow] == 0:
+                nums[slow], nums[fast] = nums[fast], nums[slow]
+
+            if nums[slow] != 0:
+                slow += 1

problems/leetcode283/python/tests/solution_test.py

@@ -0,0 +1,46 @@
+import sys
+import unittest
+from os import listdir
+from os.path import abspath, dirname, join
+
+python_source = dirname(dirname(abspath(__file__)))
+sys.path.append(python_source)
+from main.solution import Solution
+
+test_data_directory = join(dirname(python_source), 'data')
+test_cases = set([data_file.split('.')[0] for data_file in listdir(test_data_directory)])
+
+def read_input(input_file):
+    with open(input_file, 'r') as f:
+        nums = [int(num) if num != '_' else None for num in f.readline().strip().strip('][').split(',') ]
+    return nums
+
+def read_output(output_file):
+    with open(output_file, 'r') as f:
+        nums = [int(num) if num != '_' else None for num in f.readline().strip().strip('][').split(',') ]
+        return nums
+
+class TestSequenceMeta(type):
+    def __new__(mcs, name, bases, dict):
+
+        def gen_test(input_file, output_file):
+            def test(self):
+                solution = Solution()
+                input_nums = read_input(input_file)
+                expected_mums = read_output(output_file)
+                solution.moveZeroes(input_nums)
+                self.assertEqual(input_nums, expected_mums)
+            return test
+
+        for test_case in test_cases:
+            test_name = f'test_{test_case}'
+            input_file = join(test_data_directory, f'{test_case}.in')
+            output_file = join(test_data_directory, f'{test_case}.out')
+            dict[test_name] = gen_test(input_file, output_file)
+        return type.__new__(mcs, name, bases, dict)
+
+class TestSequence(unittest.TestCase, metaclass=TestSequenceMeta):
+    pass
+
+if __name__ == '__main__':
+    unittest.main()