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https://github.com/autistic-symposium/master-algorithms-py.git
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77 lines
1.5 KiB
Python
77 lines
1.5 KiB
Python
#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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# author: bt3gl
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class Node:
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def __init__(self, val):
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self.val = val
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self.next = None
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class LinkedList:
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def __init__(self):
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self.head = Node(0)
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self.len = 0
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def _loop(self , index):
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node = self.head
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p = 0
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while p < index + 1:
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node = node.next
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p += 1
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return node
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def get(self, index: int) -> int:
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if self.len <= index or index < 0:
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return -1
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node = self._loop(index)
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return node.val
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def add_at_head(self, val: int) -> None:
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self.add_at_index(0, val)
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def add_at_tail(self, val: int) -> None:
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self.add_at_index(self.len, val)
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def add_at_index(self, index: int, val: int) -> None:
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if self.len < index:
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return -1
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if index < 0:
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index = 0
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self.len += 1
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node = self.head
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for _ in range(index):
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node = node.next
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new_node = Node(val)
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new_node.next = node.next
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node.next = new_node
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def delete_at_index(self, index: int) -> None:
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if self.len <= index or index < 0:
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return -1
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self.len -= 1
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node = self.head
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for _ in range(index):
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node = node.next
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node.next = node.next.next
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