JavaScript中的JSON递归树

Question

我需要一些有关JavaScript代码的帮助。 我的目标是编写一个程序，该程序将允许生成巨大的二叉树。

编译之前，假设每个对象都有两个子代（最后一个子代除外），则指定希望的树数。

简单可视化级别= 3：

每个对象都有：

-名称-shema中的第一个字段。 还应包括有关对象编号的信息，

-Type -shema中的第二个字段。 有关物体深度的信息，

-Properties -有关对象的一些静态信息。 就我而言，情况相同，如下所示：

-儿童 。

我编写了一些代码，可以准确地从模式中重现树：

var levels = 3; //2^0, 2^1, 2^2
var level_description = [];

for (var i = 0; i < levels; i++) {
    obj = {};
    obj.level = i;
    obj.amount = Math.pow(2, i);
    obj.indexes = [];
    if (i === 0) {
        obj.indexes[0] = 0;
        level_description.push(obj);
    } else {
        for (var j = 0; j < obj.amount; j++) {
            obj.indexes[j] = obj.amount + j - 1;
        }
        level_description.push(obj);
    }
}

console.log(level_description);

var properties = [{
    "name": "trend",
    "value": "true"
}, {
    "name": "unit",
    "value": "g"
}];

var jsonString = JSON.stringify([{
    "name": "Object_" + level_description[0].indexes[0].toString(), //Object_0
    "type": "level_" + level_description[0].level.toString(), //level_0,
    "properties": properties,
    "children": [{
        "name": "Object_" + level_description[1].indexes[0].toString(), //Object_1
        "type": "level_"  + level_description[1].level.toString(), //level_1,
        "properties": properties,
        "children": [{
            "name": "Object_" + level_description[2].indexes[0].toString(), //Object_3
            "type": "level_" + level_description[2].level.toString(), //level_2,
            "properties": properties,
            "children": []
        }, {
            "name": "Object_" + level_description[2].indexes[1].toString(), //Object_4
            "type": "level_" + level_description[2].level.toString(), //level_2,
            "properties": properties,
            "children": []
        }]
    }, {
        "name": "Object_" + level_description[1].indexes[1].toString(), //Object_2
        "type": "level_" + level_description[1].level.toString(), //level_1,
        "properties": properties,
        "children": [{
            "name": "Object_" + level_description[2].indexes[2].toString(), //Object_5
            "type": "level_" + level_description[2].level.toString(), //level_2,
            "properties": properties,
            "children": []
        }, {
            "name": "Object_" + level_description[2].indexes[3].toString(), //Object_6
            "type": "level_" + level_description[2].level.toString(), //level_2,
            "properties": properties,
            "children": []
        }]
    }]
}]);

pm.globals.set('jsonString', jsonString);

但是现在我被困住了。 我很难使其具有递归性和灵活性。

我在Google光盘上上传了输出（json树）： https : //drive.google.com/drive/folders/1__nR-AXK7uKRBT4hZtiSWetyaobk72CX?usp=sharing

感谢您的任何帮助。

Answer 1

递归TreeNode生成器

我并不特别喜欢这种实现，因为它不维护您的TreeNode编号系统（广度优先），因为递归函数本质上是深度优先的，因此一个更简单，可能更好的实现是运行几个for循环，一个用于迭代每个级别，并迭代该级别的所需节点。 尽管如此，这是递归代码：

 function TreeNode(name, level, properties, children) { this.name = name; this.level = level; this.properties = properties; this.children = children; } var levels = 3; //2^0, 2^1, 2^2 var tree = new TreeNode("root", 0, {}, []); var tempIndex = 0; function generateArbitraryLevels(parent, levelsRemaining) { // last level if(levelsRemaining == 0) return; var currentLevel = parent.level + 1; parent.children.push( new TreeNode("Object_" + tempIndex++, currentLevel, {}, []) ); generateArbitraryLevels(parent.children[0], levelsRemaining - 1); parent.children.push( new TreeNode("Object_" + tempIndex++, currentLevel, {}, []) ); generateArbitraryLevels(parent.children[1], levelsRemaining - 1); } generateArbitraryLevels(tree, levels); console.log(tree); 

---

先前的答案（递归树）

因此，我针对此类问题的方法是分别实例化树中的每个节点，然后将它们彼此关联。

看看这个例子：

function TreeNode(name, type, properties, children) {
  this.name = name;
  this.type = type;
  this.properties = properties;
  this.children = children;
}

var obj1 = new TreeNode("Object_1", "level_0", {a: 1}, []);
var obj2 = new TreeNode("Object_2", "level_1", {a: 1}, []);
var obj3 = new TreeNode("Object_3", "level_1", {a: 1}, []);
var obj4 = new TreeNode("Object_4", "level_2", {a: 1}, []);
var obj5 = new TreeNode("Object_5", "level_2", {a: 1}, []);

/* TREE:
         1
        / \
       2   3
      / \
     4   5
*/


// push first level
obj1.children.push(obj2);
obj1.children.push(obj3);

// push second level
obj2.children.push(obj4);
obj2.children.push(obj5);



// Now suppose you want to "make it recursive"
// instead of number 2 having 5 as a child we are going to swap that out for 1

/* NEW TREE:
         1
        / \
       2   3
      / \
     4   1
        / \
       ..  ..
*/
// remove 5
obj2.children.pop();
// push 1
obj2.children.push(obj1);

对象变量只是对内存中实际对象的引用，因此在上面的代码中obj1 === obj2.children[1]为true

当然，这只是一个示例，要获得更大的动力，您应该存储一个映射（nodeKey-> node）并通过该映射访问节点。

希望能有所帮助

Answer 2

递归树示例：

 function makeTree(niv, max) { if (max === undefined) { max = niv; } let obj = { name: `n${max - niv}`, childrens:[] }; if (niv < 1) { return obj; } let c1 = makeTree(niv -1, max); obj.childrens.push(c1); let c2 = makeTree(niv -1, max); obj.childrens.push(c2); return obj; } console.log(makeTree(4)); 

Answer 3

我建议这种解决方案：

var cnt = -1;
var properties = {"prop1":"a","prop2":"b"};
var MAX_LEVELS = 3;

function addNode(parent, level){
  cnt = cnt + 1;
  var node = {
    "name": "Object_" + cnt,
    "type": "level_"  + level,
    "properties": properties,
    "children": []
  };

  if (level < MAX_LEVELS){
    addNode(node, level + 1);
    addNode(node, level + 1);
  }

  if (parent){
    parent.children.push(node);
  }
  else {
    return node;
  }
}
let result = addNode(null, 0);
console.log(JSON.stringify(result, null, 4))