以下是一个示例代码，用于遍历JSON输入并根据键创建类似树形结构的层次结构。代码使用递归函数来处理子级键。

def create_tree_structure(json_input, parent=None):
    if isinstance(json_input, dict):
        for key, value in json_input.items():
            node = Node(key)
            if parent is not None:
                parent.add_child(node)
            create_tree_structure(value, node)
    elif isinstance(json_input, list):
        for item in json_input:
            create_tree_structure(item, parent)

class Node:
    def __init__(self, key):
        self.key = key
        self.children = []

    def add_child(self, node):
        self.children.append(node)

    def print_tree(self, level=0):
        indent = "    " * level
        print(indent + self.key)
        for child in self.children:
            child.print_tree(level + 1)

# 示例JSON输入
json_input = {
    "key1": "value1",
    "key2": {
        "subkey1": "subvalue1",
        "subkey2": "subvalue2",
    },
    "key3": [
        {
            "subkey3": "subvalue3"
        },
        {
            "subkey4": "subvalue4"
        }
    ]
}

# 创建树形结构
root = Node("root")
create_tree_structure(json_input, root)

# 打印树形结构
root.print_tree()

运行以上代码，将生成以下树形结构：

root
    key1
    key2
        subkey1
        subkey2
    key3
        subkey3
        subkey4