import json
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class Node:
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def __init__(self, item: int, track: json, next=None):
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self.item = item
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self.track = track
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self.next = next
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class LinkedList:
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def __init__(self):
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self.head = None
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def find_by_value(self, value: int):
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# 根据值查找节点
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p = self.head
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while p and p.item != value:
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p = p.next
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return p
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def find_by_index(self, position: int):
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# 根据索引位置查找节点，需要挨个遍历
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p = self.head
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index = 0
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while p and index != position:
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p = p.next
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index += 1
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return p
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def insert_value_to_head(self, value: int, data: json):
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node = Node(value, data)
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self.insert_node_to_head(node)
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print(f"add node: {value}")
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def insert_node_to_head(self, node):
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if node:
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node.next = self.head
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self.head = node
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def insert_node_after(self, node, new_node):
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if not node or not new_node:
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return
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new_node.next = node.next
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node.next = new_node
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def insert_value_after(self, node, value, data):
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new_node = Node(value, data)
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self.insert_node_after(node, new_node)
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def insert_node_before(self, node, new_node):
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if not self.head or not node or not new_node:
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return
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if node == self.head:
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self.insert_node_to_head(new_node)
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return
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p = self.head
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while p and p.next != node:
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p = p.next
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if not p:
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return
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new_node.next = node
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p.next = new_node
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def insert_value_before(self, value: int, data: json, node):
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new_node = Node(value,data)
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self.insert_node_before(node, new_node)
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def delete_by_node(self, node):
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if not self.head or not node:
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return
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if node.next:
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node.item = node.next.item
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node.next = node.next.next
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p = self.head
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while p and p.next != node:
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p = p.next
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if not p:
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return
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p.next = node.next
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def delete_by_value(self, value: int, data: json):
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if not self.head or not value:
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return
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fake_head = Node(-1 , data)
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fake_head.next = self.head
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prev, current = fake_head, self.head
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while current:
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if current.item != value:
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prev.next = current
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prev = prev.next
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current = current.next
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if prev.next: # current.item == value
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prev.next = prev.next.next
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self.head = fake_head.next
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print(f"delete node: {value}")
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def __repr__(self):
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# print linklist，rewrite func repr or func str
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a = []
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p = self.head
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while p:
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a.append(p.track)
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p = p.next
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return " ".join(map(str, a))
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if __name__ == '__main__':
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l = LinkedList()
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for i in range(10):
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l.insert_value_to_head(i, {"name":f"w{i}"})
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node = l.find_by_value(5)
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new_name = "newNames"
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l.insert_value_before(20, {"name":f"w{new_name}"}, node)
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l.insert_value_after(node, 24, {"name":f"wafterName"})
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print(l)
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