树形结构已知子节点找父节点
已知 子节点 求父节点  
例如 已知 AAA
希望 得到 A-AA-AAA的格式
data3: [{
```
      id: 1,
      label: '一级 2',
      children: [{
        id: 3,
        label: '二级 2-1',
        children: [{
          id: 4,
          label: '三级 3-1-1'
        }, {
          id: 5,
          label: '三级 3-1-2',
          disabled: true
        }]
      }, {
        id: 2,
        label: '二级 2-2',
        disabled: true,
        children: [{
          id: 6,
          label: '三级 3-2-1'
        }, {
          id: 7,
          label: '三级 3-2-2',
          disabled: true
        }]
      }]
    }],
```
```
let find = (array, label) =>{
    let stack = [];
    let going = true;
    
    let walker = (array, label) => {
        array.forEach(item => {
            if (!going) return;
            stack.push(item['label']);
            if (item['label'] === label) {
                going = false;
            } else if (item['children']) {
                walker(item['children'], label);
            } else {
                stack.pop();
            }
        });
        if (going) stack.pop();
    }

    walker(array, label);

    return stack.join('-');
}

console.log(find(data, '三级 3-2-2'))
// 一级 2-二级 2-2-三级 3-2-2
```
应该是 `DFS`