面试题03.04.化栈为队

链接：面试题03.04.化栈为队
难度：Easy
标签：栈、设计、队列
简介：实现一个 MyQueue 类，该类用两个栈来实现一个队列。

题解 1 - typescript

• 编辑时间：2021-03-19
• 执行用时：88ms
• 内存消耗：39.2MB
• 编程语言：typescript
• 解法介绍：利用两个栈维护。

class MyQueue {
  private inStack: number[] = [];
  private outStack: number[] = [];
  get len() {
    return this.inStack.length + this.outStack.length;
  }
  push(x: number): void {
    this.inStack.push(x);
  }
  pop(): number {
    this.outStack.length === 0 && this.numberChange();
    return this.outStack.pop()!;
  }
  peek(): number {
    this.outStack.length === 0 && this.numberChange();
    return this.outStack[this.outStack.length - 1];
  }
  empty(): boolean {
    return this.len === 0;
  }
  private numberChange() {
    while (this.inStack.length > 0) {
      this.outStack.push(this.inStack.pop()!);
    }
  }
}