add tests and another approach for find_missing_number.py

README.md

@@ -54,7 +54,7 @@ Thanks for your interest in contributing! There are many ways to contribute to t
     - [single_number2](bit/single_number2.py)
     - [single_number](bit/single_number.py)
     - [subsets](bit/subsets.py)
-    - [add_without_operator](bit/add_without_operator.py)
+    - [add_bitwise_operator](bit/add_without_operator.py)
 - [calculator](calculator)
     - [math_parser](calculator/math_parser.py)
 - [dfs](dfs)

README_CN.md

@@ -48,7 +48,7 @@ python版数据结构和算法实现的简约版小示例
     - [single_number2：寻找出现1次的数（2)](bit/single_number2.py)
     - [single_number:寻找出现1次的数（1)](bit/single_number.py)
     - [subsets: 求所有子集](bit/subsets.py)
-    - [add_without_operator：无操作符的加法](bit/add_without_operator.py)
+    - [add_bitwise_operator：无操作符的加法](bit/add_without_operator.py)
 - [calculator：计算](calculator)
     - [math_parser: 数字解析](calculator/math_parser.py)
 - [dfs：深度优先搜索](dfs)

bit/add_without_operator.py

@@ -5,20 +5,27 @@
 Input: 2 3
 Output: 5
 """
+import unittest
 
 
-def addWithoutOperator(x, y):
+def add_bitwise_operator(x, y):
+
     while y != 0:
         carry = x & y
         x = x ^ y
         y = carry << 1
-    print(x)
+    return x
+
+
+class TestSuite(unittest.TestCase):
 
+    def test_add_bitwise_operator(self):
 
-def main():
-    x, y = map(int, input('Enter two positive integers: ').split())
-    addWithoutOperator(x, y)
+        self.assertEqual(5432 + 97823, add_bitwise_operator(5432, 97823))
+        self.assertEqual(0, add_bitwise_operator(0, 0))
+        self.assertEqual(10, add_bitwise_operator(10, 0))
+        self.assertEqual(10, add_bitwise_operator(0, 10))
 
 
 if __name__ == '__main__':
-    main()
+    unittest.main()

bit/count_ones.py

@@ -14,16 +14,58 @@
 
 Number of loops is
 equal to the number of 1s in the binary representation."""
+import unittest
 
-def count_ones(n):
+
+def count_ones_recur(n):
     """Using Brian Kernighan’s Algorithm. (Recursive Approach)"""
-    if not n: return 0
-    return 1 + count_ones(n & (n-1))
 
-def count_ones(n):
+    if not n:
+        return 0
+    return 1 + count_ones_recur(n & (n-1))
+
+
+def count_ones_iter(n):
     """Using Brian Kernighan’s Algorithm. (Iterative Approach)"""
+
     count = 0
     while n:
         n &= (n-1) 
         count += 1
     return count
+
+
+class TestSuite(unittest.TestCase):
+
+    def test_count_ones_recur(self):
+
+        # 8 -> 1000
+        self.assertEqual(1, count_ones_recur(8))
+
+        # 109 -> 1101101
+        self.assertEqual(5, count_ones_recur(109))
+
+        # 63 -> 111111
+        self.assertEqual(6, count_ones_recur(63))
+
+        # 0 -> 0
+        self.assertEqual(0, count_ones_recur(0))
+
+    def test_count_ones_iter(self):
+
+        # 8 -> 1000
+        self.assertEqual(1, count_ones_iter(8))
+
+        # 109 -> 1101101
+        self.assertEqual(5, count_ones_iter(109))
+
+        # 63 -> 111111
+        self.assertEqual(6, count_ones_iter(63))
+
+        # 0 -> 0
+        self.assertEqual(0, count_ones_iter(0))
+
+
+if __name__ == '__main__':
+
+    unittest.main()

bit/find_missing_number.py

@@ -1,18 +1,59 @@
-def find_missing_number(nums):
-    """Returns the missing number from a sequence of unique integers
+"""
+    Returns the missing number from a sequence of unique integers
     in range [0..n] in O(n) time and space. The difference between
     consecutive integers cannot be more than 1. If the sequence is
     already complete, the next integer in the sequence will be returned.
+"""
+import unittest
+import random
+
 
-    >>> find_missing_number(i for i in range(0, 10000) if i != 1234)
-    1234
-    >>> find_missing_number([4, 1, 3, 0, 6, 5, 2])
-    7
-    """
+def find_missing_number(nums):
 
     missing = 0
     for i, num in enumerate(nums):
         missing ^= num
         missing ^= i + 1
 
     return missing
+
+
+def find_missing_number2(nums):
+
+    num_sum = sum(nums)
+    n = len(nums)
+    total_sum = n*(n+1) // 2
+    missing = total_sum - num_sum
+    return missing
+
+
+class TestSuite(unittest.TestCase):
+
+    def setUp(self):
+        """Initialize seed."""
+        random.seed("test")
+
+    def test_find_missing_number(self):
+
+        self.assertEqual(7, find_missing_number([4, 1, 3, 0, 6, 5, 2]))
+        self.assertEqual(0, find_missing_number([1]))
+        self.assertEqual(1, find_missing_number([0]))
+
+        nums = [i for i in range(100000) if i != 12345]
+        random.shuffle(nums)
+        self.assertEqual(12345, find_missing_number(nums))
+
+    def test_find_missing_number2(self):
+
+        self.assertEqual(7, find_missing_number2([4, 1, 3, 0, 6, 5, 2]))
+        self.assertEqual(0, find_missing_number2([1]))
+        self.assertEqual(1, find_missing_number2([0]))
+
+        nums = [i for i in range(100000) if i != 12345]
+        random.shuffle(nums)
+        self.assertEqual(12345, find_missing_number2(nums))
+
+
+if __name__ == '__main__':
+
+    unittest.main()

tree.md

@@ -34,7 +34,7 @@
 │   ├── shortest_distance_from_all_buildings.py
 │   └── word_ladder.py
 ├── bit
-│   ├── add_without_operator.py
+│   ├── add_bitwise_operator.py
 │   ├── bytes_int_conversion.py
 │   ├── count_ones.py
 │   ├── find_missing_number.py