Completed Design-2

Problem_1.py

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+#Time Complexity : Ammortized O(1) 
+#Space Complexity : O(n)
+#Did this code successfully run on Leetcode : Yes
+#Any problem you faced while coding this : No
+
+class MyQueue(object):
+
+    def __init__(self):
+        self.in_st = []
+        self.out_st = []
+
+    def push(self, x):
+        self.in_st.append(x)
+
+    def pop(self):
+        if not self.out_st:
+            while self.in_st:
+                self.out_st.append(self.in_st.pop())
+        return self.out_st.pop()
+
+    def peek(self):
+        if not self.out_st:
+            while self.in_st:
+                self.out_st.append(self.in_st.pop())
+        return self.out_st[-1]
+
+
+    def empty(self):
+        if not self.in_st:
+            if not self.out_st:
+                return True
+        return False
+
+

Problem_2.py

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+#Time Complexity : Amortized O(1)
+#Space Complexity : O(n)
+#Did this code successfully run on Leetcode : Yes
+#Any problem you faced while coding this : No
+class MyHashMap:
+    class Node():
+        def __init__(self, key, value):
+            self.key = key
+            self.value = value
+            self.next = None
+
+    def __init__(self):
+        self.num_buckets = 1000
+        self.storage = [None] * self.num_buckets
+
+    def put(self, key: int, value: int):
+        hash_val = self.hash_function(key)
+        if not self.storage[hash_val]:
+            self.storage[hash_val] = self.Node(-1,-1)
+            self.storage[hash_val].next = self.Node(key, value)
+        else:
+            prev_node = self.prev_node(self.storage[hash_val], key)
+            if prev_node.next:
+                prev_node.next.value = value
+            else:
+                prev_node.next = self.Node(key, value)
+
+    def get(self, key: int):
+        hash_val = self.hash_function(key)
+        if self.storage[hash_val] is not None:
+            prev_node = self.prev_node(self.storage[hash_val], key)
+            if prev_node.next:
+                    return prev_node.next.value
+        return -1
+
+    def remove(self, key: int):
+        hash_val = self.hash_function(key)
+        if self.storage[hash_val] is not None:
+            prev_node = self.prev_node(self.storage[hash_val], key)
+            if prev_node.next is not None:
+                prev_node.next = prev_node.next.next
+
+    def prev_node(self, head, key: int) -> Node:
+        temp = prev = head
+        while temp is not None and temp.key != key:
+            prev = temp
+            temp = temp.next
+        return prev
+
+    def hash_function(self, key):
+        return key % self.num_buckets
+