**將一個沒有層級的扁平對象，轉換為樹形結構**
* * * * *
~~~
let data = [{
"province": "浙江",
"city": "杭州",
"name": "西湖"
}, {
"province": "四川",
"city": "成都",
"name": "錦里"
}, {
"province": "四川",
"city": "成都",
"name": "方所"
}, {
"province": "四川",
"city": "阿壩",
"name": "九寨溝"
}]
~~~
轉換成如下數據結構：
~~~
let tree = [{
"value": "浙江",
"children": [{
"value": "杭州",
"children": [{
"value": "西湖"
}]
}]
}, {
"value": "四川",
"children": [{
"value": "成都",
"children": [{
"value": "錦里"
}, {
"value": "方所"
}]
}, {
"value": "阿壩",
"children": [{
"value": "九寨溝"
}]
}]
}]
~~~
參照`trie`樹：
~~~
~~~
