遍歷多叉樹（遞歸、非遞歸廣度優先、深度優先）

簡單的遍歷一個樹形結構數據的幾種方法、非遞歸方法效率最好。

  1 (function (window, undefined) {
  2     var treeNodes = [
  3        {
  4             id: 1,
  5             name: '1',
  6             children: [
  7                  {
  8                       id: 11,
  9                       name: '11',
 10                       children: [
 11                            {
 12                                 id: 111,
 13                                 name: '111',
 14                                 children:[]
 15                            },
 16                            {
 17                                 id: 112,
 18                                 name: '112'
 19                            }
 20                       ]
 21                  },
 22                  {
 23                       id: 12,
 24                       name: '12',
 25                       children: []
 26                  }
 27             ],
 28             users: []
 29        },
 30        {
 31             id: 2,
 32             name: '2',
 33             children: [
 34                 {
 35                     id: 22,
 36                     name: '22',
 37                     children: []
 38                 }
 39             ]
 40        }
 41     ];
 42 
 43     //遞歸實現
 44     var parseTreeJson = function(treeNodes){
 45        var treeNodes = treeNodes || {};
 46 
 47        for (var i = 0, len = treeNodes.length; i < len; i++) {
 48 
 49             var childs = treeNodes[i].children;
 50 
 51             console.log(treeNodes[i].id);
 52 
 53             if(childs && childs.length > 0){
 54                  parseTreeJson(childs);
 55             }
 56        }
 57     };
 58 
 59     console.log('------------- 遞歸實現 ------------------');
 60     parseTreeJson(treeNodes);
 61 
 62     //非遞歸廣度優先實現
 63     var iterator1 = function (treeNodes) {
 64         var stack = [];
 65 
 66         if (!treeNodes || !treeNodes.length) return;
 67 
 68         //先將第一層節點放入棧
 69         for (var i = 0, len = treeNodes.length; i < len; i++) {
 70             stack.push(treeNodes[i]);
 71         }
 72 
 73         var item;
 74 
 75         while (stack.length) {
 76             item = stack.shift();
 77 
 78             console.log(item.id);
 79 
 80             //若是該節點有子節點，繼續添加進入棧底
 81             if (item.children && item.children.length) {
 82                 //len = item.children.length;
 83 
 84                 // for (i = 0; i < len; i++) {
 85                 //     stack.push(item.children[i]);
 86                 // }
 87 
 88                 stack = stack.concat(item.children);
 89             }
 90         }
 91     };
 92 
 93     console.log('------------- 非遞歸廣度優先實現 ------------------');
 94     iterator1(treeNodes);
 95 
 96     //非遞歸深度優先實現
 97     var iterator2 = function (treeNodes) {
 98         var stack = [];
 99 
100         if (!treeNodes || !treeNodes.length) return;
101 
102         //先將第一層節點放入棧
103         for (var i = 0, len = treeNodes.length; i < len; i++) {
104             stack.push(treeNodes[i]);
105         }
106 
107         var item;
108 
109         while (stack.length) {
110             item = stack.shift();
111 
112             console.log(item.id);
113 
114             //若是該節點有子節點，繼續添加進入棧頂
115             if (item.children && item.children.length) {
116                 // len = item.children.length;
117 
118                 // for (; len; len--) {
119                 //     stack.unshift(item.children[len - 1]);
120                 // }
121                 stack = item.children.concat(stack);
122             }
123         }
124     };
125 
126     console.log('------------- 非遞歸深度優先實現 ------------------');
127     iterator2(treeNodes);
128 })(window);