面试-腾讯-基础开发

一面

面试体验巨好，超级好，牛逼

• js题
  • setTimeout
• 算法题
  • sort 二分找最小
  • 合并有序节点
  • 查找第三大的节点
• java 多线程
  • 生产者消费者
• js模块化
• electron
  • 进程通信
• 开源项目
  • 看了我的简历写的开源项目，问了一下
    • 怎么编译kotlin到js
• Android
  • Activity生命周期 ，应该是看到我简历有写，就简单问了一下

    // 45分钟
    
    题目1（js基础）: 阅读下面代码，写出结果
    let data = { "a": 1, "b": 101 }
    function read(readUseTime) {
      return new Promise(resolve => {
        setTimeout(() => {
          resolve({...data})
        }, readUseTime)
      })
    }
    
    function write(value, writeUseTime) {
      console.info('write ',value)
      return new Promise(resolve => {
        setTimeout(() => {
          data = value
          resolve()
        }, writeUseTime)
      })
    }
    
    async function readAndWrite(key, value, readUseTime = 0, writeUseTime = 0) {
      let d = await read(readUseTime)
      d[key] = value
      await write(d, writeUseTime)
    }
    
    ;(() => {
      setTimeout(readAndWrite, 0, 'a', 2)
      setTimeout(readAndWrite, 0, 'b', 102)
      setTimeout(() => {
        // 输出结果
        console.log(data)
      }, 1000)
    })()
    { "a": 1, "b": 102 }
    
    进一步问：必需输出的是 { "a": 2, "b": 102 }，怎么修改function readAndWrite
    
    var isdo = null
    async function readAndWrite(key, value, readUseTime = 0, writeUseTime = 0) {
      if (isdo != null)
      	await isdo;
    
      isdo = new Promise(async (resolve,reject)=>{
      	 let d = await read(readUseTime)
      	d[key] = value
        resolve(d)
      }).then((res)=> {
        return new Promise(async (resolve, reject)=>{
    
      			await write(res, writeUseTime)
          	isdo = false
        	  resolve()
        })
      })
    
    }
    
    var h = setTimeout(() => { h = null; }, 1000)
    if (h == undefined) { }
    isdo = new Promise
    
    
    ;(() => {
      setTimeout(readAndWrite, 0, 'a', 2)
    
      setTimeout(readAndWrite, 0, 'b', 102)
      setTimeout(() => {
        // 输出结果
        console.log(data)
      }, 1000)
    })()
    题目2（算法）：合并两个从小到大链表的链表，使用的算法越快越好。
    比如：L1={1,3,5}, L2={2,4}, L1.merge(L2)后，L1={1,2,3,4,5}, L2={}
    class LinkNode {
      private int val;
      private LinkNode next;
      public void merge(LinkNode node) {
        // TODO 请完成实现部分
      }
    }
    
    
    function LinkNode  () {
    
      this.val  = 0;
      this.next = null
      this.merge = function (node) {
        let head = new LinkNode()
        let res = head
        let l1 = node
        let l2 = this
    
        //if
    
        while(l1 != null || l2 != null) {
          let nex
          if (l1.val < l2.val) {
            res.insert(l1)
            l1 = l1.next
            res = res.next
          } else if (l1.val > l2.val) {
            res.insert(l2)
            l2 = l2.next
            res = res.next
          }
        }
    
        if (l1 != null) {
          res = l1
        } else {
          res = l2
        }
        this.next = head.next
        this.val = head.val
      }
    
      this.insert = function (node) {
        let nex = this.next
        // let nodex = node.next
        this.next = node
        node.next = nex
        // node = nodex
      }
    }
    
    //bu yong new node
    function LinkNode  () {
    
      this.val  = 0;
      this.next = null
      this.merge = function (node) {
    
        let res = null
        let l1 = node
        let l2 = this
    
    
    
        let head = l1.val <= l2.val? l1:l2
        res = head
        //if
        if(head.val == l1.val) l1 = l1.next
        else l2 = l2.next
    
        while(l1 != null || l2 != null) {
          if (l1.val < l2.val) {
            l1.insert(l2)
            l1 = l1.next
    
          } else if (l1.val > l2.val) {
            l2 = l2.next
          }
        }
    
        if (l1 != null) {
          res = l1
        } else {
          res = l2
        }
    
      }
    
      this.insert = function (node) {
        let nex = this.next
        // let nodex = node.next
        this.next = node
        node.next = nex
        // node = nodex
      }
    }
    
    
    
    题目3（算法）：给定一个递增循环整数数组，从里面找出最小的元素，使用的算法越快越好。特别地，最小的元素可能出现在数组中间。比如：50, 52, 63, 90, 3, 8, 15, 44。
    class Problem2 {
      int findmin(int[] array) {
        // TODO 请完成实现部分
    
      }
    }
    
    
    var findMin = function (arr) {
      return arr.sort((b,a) => b-a)[0]
    }
    
    var findMin = function (arr ) {
    	let l =0
      let m = parseInt(arr.length/2)
      let r = arr.length-1
      if (arr.length==2) return Math.min(arr[0],arr[1])
      if (arr.length==1) return arr[0]
      console.info(arr)
      if (arr[l] <= arr[m]){
        return Math.min(arr[l],findMin(arr.slice(m+1)))
      }else {
        return Math.min(arr[m],findMin(arr.slice(0,m)))
      }
    }
    
    
    题目4（算法）：在二叉排序树上面找出第3大的节点。注意：不能把二叉树全量存储到另外的存储空间，比如存储到数组中，然后取出数组的第三个元素。
    class TreeNode {
        int value;
        TreeNode left, right;
    };
    
    class Problem3 {
      TreeNode find(TreeNode root) {
        // TODO 请完成实现部分
    
      }
    }
    
    var res = []
    var find = function (root) {
      findMax(root)
      return res[0]
    }
    var add = function add(arr, v) {
      if (arr.length >2) {
        arr[0] = arr[1]
        arr[1] = arr[2]
        arr[2] = v
      }
      else {
        arr.push(v)
      }
      return arr
    }
    var finMax = function (root) {
      if (root.left != null) {
        res = add(res,root.left.value)
      }
    
      res = add(res,root.value)
      if (root.right != null) {
        return findMax(root.right)
      }
    }
    
    
    
    题目5（java多线程）：阅读下面代码，在2线程环境下，设计一个方案，判断无限数据流(Stream)每个正整数是否素数，越快越好
    interface Stream {
      long get(); // 获取下一个需判断的整数
      void put(boolean result); // 返回整数是否素数的结果
      static boolean isPrimeNumber(long num) { // 判断一个整数是否素数
        if (num < 2) return false;
        for (long i = 2, s = (long) Math.sqrt(num); i <= s; i++) {
          if (num % i == 0) return false;
        }
        return true;
      }
      static Stream getInstance() {
        try {
          return (Stream) Class.forName("StreamImpl").newInstance(); // 运行环境保证不会异常
        } catch (Exception e) {
          return null;
        }
      }
    }
    比如：Stream={1,2,3,4,...}, Result={false,true,true,false,...}，注意输出顺序。
    public class Problem5 {
      private Stream stream = Stream.getInstance();
    	private long t1;
      public void thread1() throws InterruptedException {
        assert Thread.currentThread().getName() == "thread1";
        // TODO 请完成实现部分
        long t = stream.get()
        boolean b = Stream.isPrimeNumber(t)
    
        stream.notify()
        t1
        stream.put(
    
        )
        stream.wait();
      }
      public void thread2() throws InterruptedException {
        assert Thread.currentThread().getName() == "thread2";
    
        long t = stream.get()
        boolean b = Stream.isPrimeNumber(t)
        stream.wait();
        stream.put(
          Stream.isPrimeNumber(stream.get())
        )
        stream.notify()
      }
      // TODO 请完成实现部分
    
    	public static void main(String[] args) {
        Problem5 p5 = new Problem5()
        new Thread(new Runnable() {
          @Override
    			void run() {
    
          try {
            p5.thread1();
          } catch (Exception e) {
    
          }
      	},"thread1").start();
    
        new Thread(new Runnable() {
          @Override
    			void run() {
          try {
            p5.thread2();
          } catch (Exception e) {
    
          }
      	},"thread2").start();
    
      }
    }
    
    
    js基础：js模块化有哪些
    引用js模块
    require
    require('xxx.js')
    import A from 'hjk.js'
    import AC from 'jjj.vue'
    
    一个得到的是引用
    一个得到的是一个对象
    
    import 大部分时候通过 babel 实现
    
    node不支持直接使用import
    
    为了支持es6 有一个新的js运行环境 deno ？
    
    
    
    electron基础：Main进程，Renderer进程如何通信
    
    
    ipcMain
    
    ipcMain.on('xxx-event',(event,arg) =>{
     //do some
      event.sender.send('')
    }
    
    ipcRender.send
    
    -- remote
    
    
    
    build.gradle
    task complieJs (type: Exec, group: 'custom') {
        workingDir '.'
        commandLine 'kotlinc-js', '-output', 'node-publish/lib/kfmd.js' , "build/source", '-module-kind', 'commonjs'
    }
    // A problem occurred starting process 'command 'kotlinc-js''
    
    var core = kfmd.Core()
    var html = core.setContainorClass('demo').trans(a)
    
    
    Android

二面 2020/03/30 8:30

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