Leet code day 4 challehge solved

Author: arc-arnob

leet_code_questions/dist/stack-using-two-queues.js

@@ -0,0 +1,69 @@
+var MyStack = /** @class */ (function () {
+    function MyStack() {
+        // create two queues, q1 and q2
+        this.q1 = new Queue();
+        this.q2 = new Queue();
+    }
+    MyStack.prototype.push = function (x) {
+        this.q2.enqueue(x);
+        // Dequeue all q1 and enqueue it to q2
+        while (!this.q1.isEmpty()) {
+            var poppedElement = this.q1.dequeue();
+            if (poppedElement !== null) {
+                this.q2.enqueue(poppedElement);
+            }
+        }
+        // Enqueue all q2 to q1
+        while (!this.q2.isEmpty()) {
+            var poppedElement = this.q2.dequeue();
+            if (poppedElement !== null) {
+                this.q1.enqueue(poppedElement);
+            }
+        }
+        // Clear q2
+        this.q2.clear();
+    };
+    MyStack.prototype.pop = function () {
+        return this.q1.dequeue();
+    };
+    MyStack.prototype.top = function () {
+        return this.q1.front();
+    };
+    MyStack.prototype.empty = function () {
+        return this.q1.isEmpty();
+    };
+    return MyStack;
+}());
+var Queue = /** @class */ (function () {
+    function Queue() {
+        this.items = [];
+    }
+    Queue.prototype.enqueue = function (x) {
+        this.items.push(x);
+    };
+    Queue.prototype.dequeue = function () {
+        var _a, _b;
+        return (_b = (_a = this.items) === null || _a === void 0 ? void 0 : _a.shift()) !== null && _b !== void 0 ? _b : null;
+    };
+    Queue.prototype.front = function () {
+        return this.items[0];
+    };
+    Queue.prototype.isEmpty = function () {
+        return this.items.length === 0;
+    };
+    Queue.prototype.clear = function () {
+        this.items = [];
+    };
+    return Queue;
+}());
+var obj = new MyStack();
+obj.push(10);
+obj.push(20);
+obj.push(30);
+obj.push(40);
+var param_2 = obj.pop();
+var param_2 = obj.pop();
+var param_2 = obj.pop();
+var param_3 = obj.top();
+var param_4 = obj.empty();
+console.log(param_4, param_3);

leet_code_questions/stack-using-two-queues.ts

@@ -0,0 +1,90 @@
+class MyStack {
+	private q1: Queue<number>;
+	private q2: Queue<number>;
+	constructor() {
+		// create two queues, q1 and q2
+		this.q1 = new Queue<number>();
+		this.q2 = new Queue<number>();
+	}
+	push(x: number): void {
+
+		this.q2.enqueue(x);
+
+		// Dequeue all q1 and enqueue it to q2
+		while (!this.q1.isEmpty()) {
+			let poppedElement: number | null = this.q1.dequeue()
+			if (poppedElement !== null) {
+				this.q2.enqueue(poppedElement);
+			}
+		}
+
+		// Enqueue all q2 to q1
+		while (!this.q2.isEmpty()) {
+			let poppedElement: number | null = this.q2.dequeue()
+			if (poppedElement !== null) {
+				this.q1.enqueue(poppedElement);
+			}
+
+		}
+
+		// Clear q2
+		this.q2.clear();
+	}
+
+	pop(): number | null {
+		return this.q1.dequeue();
+	}
+
+	top(): number {
+		return this.q1.front();
+	}
+
+	empty(): boolean {
+		return this.q1.isEmpty();
+	}
+
+
+}
+
+class Queue<T> {
+	private items: T[];
+	constructor() {
+		this.items = [];
+	}
+
+	enqueue(x: T): void {
+		this.items.push(x);
+	}
+
+	dequeue(): T | null {
+		return this.items?.shift() ?? null;
+	}
+
+	front(): T {
+		return this.items[0];
+	}
+
+	isEmpty(): boolean {
+		return this.items.length === 0;
+	}
+
+	clear(): void {
+		this.items = [];
+	}
+
+}
+
+
+var obj = new MyStack()
+obj.push(10);
+obj.push(20);
+obj.push(30);
+obj.push(40);
+var param_2 = obj.pop()
+var param_2 = obj.pop()
+var param_2 = obj.pop()
+var param_3 = obj.top()
+var param_4 = obj.empty()
+
+console.log(param_4, param_3);
+