Completed Design 2

design_hashmap_706.py

@@ -0,0 +1,52 @@
+class ListNode:
+    def __init__(self, key, value):
+        self.key = key
+        self.value = value
+        self.next = None
+
+class MyHashMap:
+
+    def __init__(self):
+        self.size = 1000
+        self.table = [None] * self.size
+
+    def _index(self, key: int) -> int:
+        return key % self.size
+
+    def put(self, key: int, value: int) -> None:
+        idx = self._index(key)
+        if not self.table[idx]:
+            self.table[idx] = ListNode(key, value)
+            return
+        current = self.table[idx]
+        while current:
+            if current.key == key:
+                current.value = value
+                return
+            if not current.next:
+                current.next = ListNode(key, value)
+                return
+            current = current.next
+
+    def get(self, key: int) -> int:
+        idx = self._index(key)
+        current = self.table[idx]
+        while current:
+            if current.key == key:
+                return current.value
+            current = current.next
+        return -1
+
+    def remove(self, key: int) -> None:
+        idx = self._index(key)
+        current = self.table[idx]
+        if not current:
+            return
+        if current.key == key:
+            self.table[idx] = current.next
+            return
+        while current.next:
+            if current.next.key == key:
+                current.next = current.next.next
+                return
+            current = current.next

min_stack_155.py

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+class MinStack:
+
+    def __init__(self):
+        self.s = []
+        self.minstack = []
+
+    def push(self, val: int) -> None:
+        self.s.append(val)
+        min_val = min(val, self.minstack[-1] if self.minstack else val)
+        self.minstack.append(min_val)
+
+    def pop(self) -> None:
+        self.s.pop()
+        self.minstack.pop()
+
+    def top(self) -> int:
+        return self.s[-1]
+
+    def getMin(self) -> int:
+        return self.minstack[-1]

queue_using_stack_232.py

@@ -0,0 +1,26 @@
+class MyQueue:
+
+    def __init__(self):
+        self.stack1 = []
+        self.stack2 = []
+
+    def push(self, x: int) -> None:
+        self.stack1.append(x)
+        while self.stack1:
+            self.stack2.append(self.stack1.pop())
+
+    def pop(self) -> int:
+        return self.stack2.pop(0)
+
+    def peek(self) -> int:
+        return self.stack2[0]
+
+    def empty(self) -> bool:
+        return not self.stack2
+
+# Your MyQueue object will be instantiated and called as such:
+# obj = MyQueue()
+# obj.push(x)
+# param_2 = obj.pop()
+# param_3 = obj.peek()
+# param_4 = obj.empty()