dynamic-programming

.vscode/settings.json

@@ -0,0 +1,17 @@
+{
+    "python.testing.unittestArgs": [
+        "-v",
+        "-s",
+        "./tests",
+        "-p",
+        "*test.py"
+    ],
+    "python.testing.pytestEnabled": true,
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestArgs": [
+        "tests"
+    ],
+    "cSpell.words": [
+        "curr"
+    ]
+}

lib/max_subarray.py

@@ -4,9 +4,31 @@ def max_sub_array(nums):
         Returns 0 if  nums is None or an empty list.
         Time Complexity: ?
         Space Complexity: ?
+        Does this have to be contiguous? 
     """
     if nums == None:
         return 0
     if len(nums) == 0:
         return 0
-    pass
+# # Arrange
+    # input = [50, 3, -50, 50, 3]
+    # output = 56
+    # input1 = [-2, -1]
+    # output = [-1]
+
+    max_so_far = 0
+    max_ending = 0
+
+    for i in nums:
+        max_ending += i
+
+        if  max_ending > max_so_far:
+            max_so_far = max_ending
+
+        # when max sum is less than 0/negative num 
+        if max_so_far <= 0:
+            return max(nums)
+    return max_so_far
+
+# Run Time: 0(n)
+# Space: O(1)

lib/newman_conway.py

@@ -4,7 +4,21 @@
 # Space Complexity: ?
 def newman_conway(num):
     """ Returns a list of the Newman Conway numbers for the given value.
-        Time Complexity: ?
-        Space Complexity: ?
+        Time Complexity: o(n)
+        Space Complexity: 0(n)
     """
-    pass
+    # count of num and the num itself 
+    # input = 13
+    # output = 1113 -> 3113 -> 132113-> 1113122113 -> 311311222113 -> 13211321322113 ->
+    if num == 0:
+        raise ValueError
+    if num == 1:
+        return "1"
+
+    sequence = [0, 1, 1]
+    for val in range(3, num+1):
+        nc = sequence[sequence[val - 1]] + sequence[val - sequence[val - 1]]
+        sequence.append(nc)
+
+    return ' '.join([str(s) for s in sequence[1:]])
+