# 前端面试题及答案汇总(五) 51-60

var a = { n: 1 };
var b = a;
a.x = a = { n: 2 };

console.log(a.x); // undefined
console.log(b.x); // {n: 2}

function bubbleSort(arr) {
  if (!arr || arr.length === 0) {
    return null;
  }
  for (let i = 0, len = arr.length; i < len; i++) {
    for (let j = i + 1; j < len; j++) {
      if (arr[i] > arr[j]) {
        let temp = arr[j];
        arr[j] = arr[i];
        arr[i] = temp;
      }
    }
  }
  return arr;
}
const arr = [1, 5, 2, 3, 8, 4, 7];
console.log(bubbleSort(arr));

// 改进冒泡排序
function bubbleSort1(arr) {
  let i = arr.length - 1;

  while (i > 0) {
    let pos = 0;
    for (let j = 0; j < i; j++) {
      if (arr[j] > arr[j + 1]) {
        pos = j;
        const temp = arr[j];
        arr[j] = arr[j + 1];
        arr[j + 1] = temp;
      }
    }
    i = pos;
  }
  console.log(arr);
}

let obj = { 1: 222, 2: 123, 5: 888 };
function transform(obj) {
  let res = new Array(12).fill(null);
  for (let key in obj) {
    res[key - 1] = obj[key];
  }
  return res;
}
console.log(transform(obj));

LazyMan("Tony");
// Hi I am Tony

LazyMan("Tony")
  .sleep(10)
  .eat("lunch");
// Hi I am Tony
// 等待了10秒...
// I am eating lunch

LazyMan("Tony")
  .eat("lunch")
  .sleep(10)
  .eat("dinner");
// Hi I am Tony
// I am eating lunch
// 等待了10秒...
// I am eating diner

LazyMan("Tony")
  .eat("lunch")
  .eat("dinner")
  .sleepFirst(5)
  .sleep(10)
  .eat("junk food");
// Hi I am Tony
// 等待了5秒...
// I am eating lunch
// I am eating dinner
// 等待了10秒...
// I am eating junk food

class LazyManClass {
  constructor(name) {
    this.taskList = [];
    console.log(`Hi I am ${name}`);
    setTimeout(() => {
      this.next();
    }, 0);
  }
  sleep(time) {
    const fn = () => {
      setTimeout(() => {
        this.next();
      }, time * 1000);
    };
    this.taskList.push(fn);
    return this;
  }
  eat(food) {
    const fn = () => {
      console.log(`I am eating ${food}`);
      this.next();
    };
    this.taskList.push(fn);
    return this;
  }
  sleepFirst(time) {
    const fn = () => {
      setTimeout(() => {
        this.next();
      }, time * 1000);
    };
    this.taskList.unshift(fn);
    return this;
  }
  next() {
    const fn = this.taskList.shift();
    fn && fn();
  }
}
function LazyMan(name) {
  return new LazyManClass(name);
}
LazyMan("Tony")
  .eat("lunch")
  .eat("dinner")
  .sleepFirst(2)
  .sleep(1)
  .eat("junk food");

function union(arr1, arr2) {
  if (!arr1 || !arr2 || arr1.length === 0 || arr2.length === 0) {
    return null;
  }
  let res = [];
  arr1.sort((a, b) => a - b);
  arr2.sort((a, b) => a - b);
  let p1 = 0;
  let p2 = 0;
  const len1 = arr1.length;
  const len2 = arr2.length;
  while (p1 < len1 && p2 < len2) {
    if (arr1[p1] === arr2[p2]) {
      res.push(arr1[p1]);
      p1++;
      p2++;
    } else if (arr1[p1] < arr2[p2]) {
      p1++;
    } else {
      p2++;
    }
  }
  return res;
}

const arr1 = [1, 2, 5, 3, 63, 42];
const arr2 = [42, 35, 1, 5, 111, 662, 77, 5];
console.log(union(arr1, arr2));