https://leetcode-cn.com/problems/implement-queue-using-stacks/

    1. class MyQueue {
    2.   private inStack: number[];
    3.   private outStack: number[];
    5.   constructor() {
    6.     this.inStack = [];
    7.     this.outStack = [];
    8.   }
    10.   push(x: number): void {
    11.     this.inStack.push(x);
    12.   }
    14.   pop(): number {
    15.     if (this.outStack.length === 0) {
    16.       while (this.inStack.length) {
    17.         this.outStack.push(this.inStack.pop());
    18.       }
    19.     }
    20.     if (this.outStack.length === 0) {
    21.       return null;
    22.     }
    23.     return this.outStack.pop();
    24.   }
    26.   peek(): number {
    27.     if (this.outStack.length === 0) {
    28.       while (this.inStack.length) {
    29.         this.outStack.push(this.inStack.pop());
    30.       }
    31.     }
    32.     if (this.outStack.length === 0) {
    33.       return null;
    34.     }
    35.     return this.outStack[this.outStack.length - 1];
    36.   }
    38.   empty(): boolean {
    39.     return !this.inStack.length && !this.outStack.length;
    40.   }
    41. }

    https://bigfrontend.dev/zh/problem/the-angle-between-hour-hand-and-minute-hand-of-a-clock

    
/**
 * @param {string} time
 * @returns {number} 
 */
function angle(time) {
  let [hours, minutes] = time.split(':').map(Number);
  // 12小时制
  hours = hours % 12;
  // 每分钟6度，一圈为60分钟
  const mDPM = 360 / 60;
  // 每小时30度，一圈12小时（整点的情况下）
  const hDPM = 360 / 12;
  // 超出部分，比如01:30，时针度数在1和2正中间。
  // 一分钟，时针偏移0.5度，30分钟时针偏移15度
  const extra = 360 / 12 / 60 * minutes;
  // 时针度数
  const hoursAngle = hDPM * hours + extra;
  // 分针度数
  const minutesAngle = mDPM * minutes;
  // 计算角度
  const diff = Math.abs(hoursAngle - minutesAngle);
  // 四舍五入，是否超过180
  return Math.round(Math.min(diff, 360 - diff));
}