Merge pull request #1048 from xiaofei-2020/stack3

添加（0225.用队列实现栈.md）：增加typescript版本

problems/0225.用队列实现栈.md

@@ -598,7 +598,80 @@ MyStack.prototype.empty = function() {
 
 ```
 
+TypeScript:
+
+版本一：使用两个队列模拟栈
+
+```typescript
+class MyStack {
+    private queue: number[];
+    private tempQueue: number[];
+    constructor() {
+        this.queue = [];
+        this.tempQueue = [];
+    }
+
+    push(x: number): void {
+        this.queue.push(x);
+    }
+
+    pop(): number {
+        for (let i = 0, length = this.queue.length - 1; i < length; i++) {
+            this.tempQueue.push(this.queue.shift()!);
+        }
+        let res: number = this.queue.pop()!;
+        let temp: number[] = this.queue;
+        this.queue = this.tempQueue;
+        this.tempQueue = temp;
+        return res;
+    }
+
+    top(): number {
+        let res: number = this.pop();
+        this.push(res);
+        return res;
+    }
+
+    empty(): boolean {
+        return this.queue.length === 0;
+    }
+}
+```
+
+版本二：使用一个队列模拟栈
+
+```typescript
+class MyStack {
+    private queue: number[];
+    constructor() {
+        this.queue = [];
+    }
+
+    push(x: number): void {
+        this.queue.push(x);
+    }
+
+    pop(): number {
+        for (let i = 0, length = this.queue.length - 1; i < length; i++) {
+            this.queue.push(this.queue.shift()!);
+        }
+        return this.queue.shift()!;
+    }
+
+    top(): number {
+        let res: number = this.pop();
+        this.push(res);
+        return res;
+    }
+
+    empty(): boolean {
+        return this.queue.length === 0;
+    }
+}
+```
+
 Swift
+
 ```Swift
 // 定义一个队列数据结构
 class Queue {