adding algo

src/my_project/interviews/top_150_questions_round_22/ex_52_min_stack.py

@@ -0,0 +1,21 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class MinStack:
+    def __init__(self):
+        self.A = []
+        self.M = []
+
+    def push(self, x):
+        self.A.append(x)
+        self.M.append(x if not self.M else min(x, self.M[-1]))    
+
+    def pop(self):
+        self.A.pop()
+        self.M.pop()
+
+    def top(self):
+        return self.A[-1]
+
+    def getMin(self):
+        return self.M[-1]

src/my_project/interviews_typescript/top_150_questions_round_1/test_52_min_stack_round_22.ts

@@ -0,0 +1,33 @@
+class MinStack {
+
+    private stack: number[]
+    private minStack: number[]
+
+    constructor() {
+        this.stack = [];
+        this.minStack = [];
+
+    }
+
+    push(val: number): void {
+        this.stack.push(val)
+        if (this.minStack.length === 0){
+            this.minStack.push(val)
+        }else{
+            this.minStack.push(Math.min(val, this.minStack[this.minStack.length - 1]))
+        }        
+    }
+
+    pop(): void {
+        this.stack.pop()
+        this.minStack.pop()
+    }
+
+    top(): number {
+        return this.stack[this.stack.length - 1]
+    }
+
+    getMin(): number {
+        return this.minStack[this.minStack.length - 1]
+    }
+}

tests/test_150_questions_round_22/test_52_min_stack_round_22.py

@@ -0,0 +1,36 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_52_min_stack import MinStack
+
+class MinStackTestCase(unittest.TestCase):
+
+    def test_first_pattern(self):
+        commands = ["MinStack","push","push","push","getMin",
+                    "pop","top","getMin"]
+        args = [[],[-2],[0],[-3],[],[],[],[]]
+
+        expected_output = [None,None,None,None,-3,None,0,-2]
+
+        min_stack = None
+        actual_output = []
+
+        for i, command in enumerate(commands):
+            if command == "MinStack":
+                min_stack = MinStack()
+                actual_output.append(None)
+            elif command == "push":
+                min_stack.push(args[i][0])
+                actual_output.append(None)
+            elif command == "pop":
+                min_stack.pop()
+                actual_output.append(None)
+            elif command == "top":
+                result = min_stack.top()
+                actual_output.append(result)
+            elif command == "getMin":
+                result = min_stack.getMin()
+                actual_output.append(result)
+
+        self.assertEqual(actual_output, expected_output)
+
+