Design-2

2stacks_queue.py

@@ -0,0 +1,44 @@
+"""
+// Time Complexity : o(1) for for all operations except pop which is amortized o(1)
+// Space Complexity : o(n)
+// Did this code successfully run on Leetcode : yes
+// Any problem you faced while coding this : None
+
+"""
+
+
+class MyQueue:
+
+    def __init__(self):
+        self.in_stack = []
+        self.out_stack = []
+
+    def push(self, x: int) -> None:
+        self.in_stack.append(x)
+
+    def pop(self) -> int:
+        if not self.in_stack and not self.out_stack:
+            return -1
+        if not self.out_stack:
+            while self.in_stack:
+                self.out_stack.append(self.in_stack.pop())
+        return self.out_stack.pop()
+
+    def peek(self) -> int:
+        if not self.in_stack and not self.out_stack:
+            return -1
+        if not self.out_stack:
+            return self.in_stack[0]
+        if self.out_stack:
+            return self.out_stack[-1]
+
+    def empty(self) -> bool:
+        return len(self.in_stack) == 0 and len(self.out_stack) == 0
+
+
+# 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()

hashmap.py

@@ -0,0 +1,46 @@
+"""
+// Time Complexity : o(1) for for all operations
+// Space Complexity : o(n)
+// Did this code successfully run on Leetcode : yes
+// Any problem you faced while coding this : null checks did not check instead of == None in python and it failed for get(0)
+
+"""
+
+
+class MyHashMap:
+
+    def __init__(self):
+        self.map = [None] * 1000
+        self.divisor = 1000
+
+    def put(self, key: int, value: int) -> None:
+        main_index = key % self.divisor
+        if not self.map[main_index]:
+            self.map[main_index] = [None] * 1000 if main_index != 0 else [None] * 1001
+        secondary_index = key // self.divisor
+        self.map[main_index][secondary_index] = value
+
+    def get(self, key: int) -> int:
+        main_index = key % self.divisor
+        if not self.map[main_index]:
+            return -1
+        secondary_index = key // self.divisor
+        if self.map[main_index][secondary_index] == None:
+            return -1
+        return self.map[main_index][secondary_index]
+
+    def remove(self, key: int) -> None:
+        main_index = key % self.divisor
+        if not self.map[main_index]:
+            return
+        secondary_index = key // self.divisor
+        if self.map[main_index][secondary_index] == None:
+            return
+        self.map[main_index][secondary_index] = None
+
+
+# Your MyHashMap object will be instantiated and called as such:
+# obj = MyHashMap()
+# obj.put(key,value)
+# param_2 = obj.get(key)
+# obj.remove(key)