[Feat] Add more implementation

Author: AustinPardosi

Diff for: 191-NumberOf1Bits.py

@@ -0,0 +1,9 @@
+class Solution:
+    def hammingWeight(self, n: int) -> int:
+        result = 0
+        binString = bin(n)
+        for char in binString:
+            if char == "1":
+                result += 1
+
+        return result

Diff for: 347-TopKFrequentElements.py

@@ -0,0 +1,19 @@
+class Solution:
+    def topKFrequent(self, nums: List[int], k: int) -> List[int]:
+        hashMap = {}
+        for num in nums:
+            if num not in hashMap:
+                hashMap[num] = 1
+            else:
+                hashMap[num] += 1
+
+        freq = [[] for i in range(len(nums) + 1)]
+        for n, val in hashMap.items():
+            freq[val].append(n)
+
+        res = []
+        for i in range(len(freq) - 1, 0, -1):
+            for n in freq[i]:
+                res.append(n)
+                if len(res) == k:
+                    return res

Diff for: 53-MaximumSubarray.py

@@ -0,0 +1,11 @@
+class Solution:
+    def maxSubArray(self, nums: List[int]) -> int:
+        maxSum = nums[0]
+        tempSum = 0
+
+        for num in nums:
+            if tempSum < 0:
+                tempSum = 0
+            tempSum += num
+            maxSum = max(maxSum, tempSum)
+        return maxSum

Diff for: 543-DiameterOfBinaryTree.py

@@ -0,0 +1,24 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def __init__(self):
+        self.max_diameter = 0
+
+    def dfs(self, root: Optional[TreeNode]) -> int:
+        if root == None:
+            return 0
+
+        leftDiameter = self.dfs(root.left)
+        rightDiameter = self.dfs(root.right)
+
+        self.max_diameter = max(self.max_diameter, leftDiameter + rightDiameter)
+
+        return 1 + max(leftDiameter, rightDiameter)
+
+    def diameterOfBinaryTree(self, root: Optional[TreeNode]) -> int:
+        self.dfs(root)
+        return self.max_diameter