算法题：

  • 链接：https://leetcode-cn.com/problems/same-tree/
  • 描述：
    • 给你两棵二叉树的根节点 p 和 q ，编写一个函数来检验这两棵树是否相同。
    • 如果两个树在结构上相同，并且节点具有相同的值，则认为它们是相同的。
  • 解题 ```javascript /**
    • @param {TreeNode} p
    • @param {TreeNode} q
    • @return {boolean} */ var isSameTree = function(p, q) { if(p===null && q===null) {
      1. return true
      } if (p===null || q===null) {
      1. return false
      } if (p.val !==q.val) {
      1. return false
      }
  1. return isSameTree(p.left,q.left) && isSameTree(p.right,q.right)

};

  3. <a name="LbhHM"></a>
  4. ### 手写题：
  6. - 链接：[https://bigfrontend.dev/zh/problem/virtual-dom-v-jsx-2](https://bigfrontend.dev/zh/problem/virtual-dom-v-jsx-2)
  7. - 解题：
  8. ```javascript
  9. function checkForClosing(str, i) {
  10.       if (str[i] == "/") return true;
  11.       if (str[i] == ">") return false;
  12.       return checkForClosing(str, i + 1);
  13.     }
  15.     function parseChild(str) {
  16.       console.log('str',str)
  17.       console.log('===============')
  18.       // str = str.trim();
  19.       let child = [];
  20.       let text = "";
  21.       for (var i = 0; i < str.length; i++) {
  22.         if (str[i] == "<" && checkForClosing(str, i)) {
  23.           console.log('break')
  24.           break;
  25.         }
  27.         if (str[i] == "<") {
  28.           let newStr = str.slice(i);
  29.           const result = parse(newStr);
  30.           child.push(text);
  31.           child.push(result);
  32.           i += result.endClosing;
  33.           text = "";
  34.           continue;
  35.         }
  36.         else {
  37.           text += str[i];
  38.         }
  39.       }
  40.       console.log('outer')
  41.       child.push(text);
  42.       const nextTag = i;
  43.       if (nextTag == 0) return [null, nextTag];
  44.       return [child, nextTag];
  45.     }
  47.     function parseTag(str) {
  48.       let isClosing = false;
  49.       let closeOpening = str.indexOf(">");
  50.       let tag = str.slice(1, closeOpening).trim();
  52.       if (tag[0] == "/") {
  53.         isClosing = true;
  54.         tag = tag.slice(1).trim();
  55.       }
  57.       return [tag, closeOpening, isClosing]
  58.     }
  60.     function parse(code) {
  61.       // your code here
  62.       code = code.trim();
  63.       if (code[0] !== "<" || code[code.length - 1] !== ">") {
  64.         throw new Error("");
  65.       }
  66.       if (code.split("<").length !== code.split(">").length) {
  67.         throw new Error("");
  68.       }
  70.       let i = 1;
  71.       var [opening, endOpening, isClosing] = parseTag(code, i);
  72.       code = code.substr(endOpening + 1, code.length);
  73.       i += endOpening;
  74.       var [child, endChild] = parseChild(code, i);
  75.       code = code.substr(endChild, code.length);
  76.       i += endChild;
  77.       var [closing, endClosing, isClosing] = parseTag(code, i);
  78.       code = code.substr(endClosing + 1, code.length);
  79.       i += endClosing;
  81.       if (!isClosing) throw new Error("Closing element not found");
  82.       if (opening !== closing) {
  83.         throw new Error("Opening and closing doesn't match")
  84.       }
  86.       let res = {
  87.         opening,
  88.         child: [child],
  89.         closing,
  90.         endClosing: i
  91.       }
  92.       return res;
  93.     }
  95.     /**
  96.      * @param {any} your AST
  97.      * @returns {string} 
  98.      */
  99.     function generate(ast) {
  100.       // your code here
  102.       if (ast.child[0] == null) {
  103.         return h(`${ast.opening}`, null);
  104.       } else {
  105.         let childrens = ast.child[0];
  106.         let newChildrens = []
  107.         for (let i = 0; i < childrens.length; i++) {
  108.           if (childrens[i] instanceof Object) {
  109.             newChildrens.push(generate(childrens[i]))
  110.           } else {
  111.             childrens[i] != "" && newChildrens.push(childrens[i]);
  112.           }
  113.         }
  114.         let opening;
  115.         if (`${ast.opening}`[0] == `${ast.opening}`[0].toUpperCase()) {
  116.           opening = Heading;
  117.         } else {
  118.           opening = `${ast.opening}`;
  119.         }
  120.         return h(opening, null, ...newChildrens);
  121.       }
  122.     }
  • 自己没写出来，最后啃别人的代码啃懂了，还需要多练习几次。加强对源码的阅读和临摹，之前这是这块逻辑懂了，但是写起来太费劲了。整了一个下午