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translation: Add Python and Java code for EN version (#1345)
* Add the intial translation of code of all the languages * test * revert * Remove * Add Python and Java code for EN version
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Yudong Jin
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"""
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File: array.py
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Created Time: 2022-11-25
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Author: krahets (krahets@163.com)
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"""
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import random
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def random_access(nums: list[int]) -> int:
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"""Random access to elements"""
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# Randomly select a number from the interval [0, len(nums)-1]
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random_index = random.randint(0, len(nums) - 1)
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# Retrieve and return a random element
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random_num = nums[random_index]
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return random_num
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# Note that Python's list is a dynamic array that can be extended
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# For ease of learning, this function treats the list as a static array
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def extend(nums: list[int], enlarge: int) -> list[int]:
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"""Extend array length"""
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# Initialize an extended length array
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res = [0] * (len(nums) + enlarge)
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# Copy all elements from the original array to the new array
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for i in range(len(nums)):
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res[i] = nums[i]
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# Return the new array after expansion
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return res
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def insert(nums: list[int], num: int, index: int):
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"""Insert element num at `index`"""
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# Move all elements after `index` one position backward
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for i in range(len(nums) - 1, index, -1):
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nums[i] = nums[i - 1]
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# Assign num to the element at index
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nums[index] = num
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def remove(nums: list[int], index: int):
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"""Remove the element at `index`"""
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# Move all elements after `index` one position forward
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for i in range(index, len(nums) - 1):
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nums[i] = nums[i + 1]
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def traverse(nums: list[int]):
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"""Traverse array"""
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count = 0
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# Traverse array by index
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for i in range(len(nums)):
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count += nums[i]
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# Traverse array elements
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for num in nums:
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count += num
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# Traverse both data index and elements
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for i, num in enumerate(nums):
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count += nums[i]
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count += num
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def find(nums: list[int], target: int) -> int:
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"""Search for a specified element in the array"""
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for i in range(len(nums)):
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if nums[i] == target:
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return i
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return -1
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"""Driver Code"""
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if __name__ == "__main__":
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# Initialize an array
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arr = [0] * 5
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print("Array arr =", arr)
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nums = [1, 3, 2, 5, 4]
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print("Array nums =", nums)
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# Random access
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random_num: int = random_access(nums)
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print("Retrieve a random element in nums", random_num)
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# Length extension
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nums: list[int] = extend(nums, 3)
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print("Extend the array length to 8, resulting in nums =", nums)
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# Insert element
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insert(nums, 6, 3)
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print("Insert number 6 at index 3, resulting in nums =", nums)
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# Remove element
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remove(nums, 2)
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print("Remove the element at index 2, resulting in nums =", nums)
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# Traverse array
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traverse(nums)
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# Search for elements
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index: int = find(nums, 3)
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print("Search for element 3 in nums, resulting in index =", index)
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"""
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File: linked_list.py
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Created Time: 2022-11-25
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Author: krahets (krahets@163.com)
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"""
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import sys
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from pathlib import Path
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sys.path.append(str(Path(__file__).parent.parent))
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from modules import ListNode, print_linked_list
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def insert(n0: ListNode, P: ListNode):
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"""Insert node P after node n0 in the linked list"""
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n1 = n0.next
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P.next = n1
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n0.next = P
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def remove(n0: ListNode):
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"""Remove the first node after node n0 in the linked list"""
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if not n0.next:
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return
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# n0 -> P -> n1
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P = n0.next
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n1 = P.next
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n0.next = n1
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def access(head: ListNode, index: int) -> ListNode | None:
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"""Access the node at `index` in the linked list"""
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for _ in range(index):
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if not head:
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return None
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head = head.next
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return head
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def find(head: ListNode, target: int) -> int:
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"""Search for the first node with value target in the linked list"""
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index = 0
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while head:
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if head.val == target:
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return index
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head = head.next
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index += 1
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return -1
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"""Driver Code"""
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if __name__ == "__main__":
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# Initialize linked list
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# Initialize each node
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n0 = ListNode(1)
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n1 = ListNode(3)
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n2 = ListNode(2)
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n3 = ListNode(5)
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n4 = ListNode(4)
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# Build references between nodes
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n0.next = n1
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n1.next = n2
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n2.next = n3
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n3.next = n4
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print("The initialized linked list is")
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print_linked_list(n0)
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# Insert node
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p = ListNode(0)
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insert(n0, p)
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print("Linked list after inserting the node is")
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print_linked_list(n0)
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# Remove node
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remove(n0)
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print("Linked list after removing the node is")
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print_linked_list(n0)
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# Access node
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node: ListNode = access(n0, 3)
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print("The value of the node at index 3 in the linked list = {}".format(node.val))
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# Search node
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index: int = find(n0, 2)
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print("The index of the node with value 2 in the linked list = {}".format(index))
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"""
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File: list.py
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Created Time: 2022-11-25
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Author: krahets (krahets@163.com)
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"""
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"""Driver Code"""
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if __name__ == "__main__":
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# Initialize list
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nums: list[int] = [1, 3, 2, 5, 4]
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print("\nList nums =", nums)
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# Access element
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x: int = nums[1]
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print("\nAccess the element at index 1, resulting in x =", x)
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# Update element
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nums[1] = 0
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print("\nUpdate the element at index 1 to 0, resulting in nums =", nums)
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# Clear list
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nums.clear()
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print("\nAfter clearing the list, nums =", nums)
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# Add element at the end
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nums.append(1)
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nums.append(3)
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nums.append(2)
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nums.append(5)
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nums.append(4)
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print("\nAfter adding the element, nums =", nums)
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# Insert element in the middle
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nums.insert(3, 6)
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print("\nInsert number 6 at index 3, resulting in nums =", nums)
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# Remove element
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nums.pop(3)
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print("\nRemove the element at index 3, resulting in nums =", nums)
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# Traverse the list by index
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count = 0
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for i in range(len(nums)):
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count += nums[i]
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# Traverse the list elements
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for num in nums:
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count += num
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# Concatenate two lists
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nums1 = [6, 8, 7, 10, 9]
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nums += nums1
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print("\nConcatenate list nums1 to nums, resulting in nums =", nums)
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# Sort list
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nums.sort()
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print("\nAfter sorting the list, nums =", nums)
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@@ -0,0 +1,118 @@
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"""
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File: my_list.py
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Created Time: 2022-11-25
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Author: krahets (krahets@163.com)
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"""
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class MyList:
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"""List class"""
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def __init__(self):
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"""Constructor"""
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self._capacity: int = 10 # List capacity
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self._arr: list[int] = [0] * self._capacity # Array (stores list elements)
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self._size: int = 0 # List length (current number of elements)
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self._extend_ratio: int = 2 # Multiple for each list expansion
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def size(self) -> int:
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"""Get list length (current number of elements)"""
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return self._size
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def capacity(self) -> int:
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"""Get list capacity"""
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return self._capacity
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def get(self, index: int) -> int:
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"""Access element"""
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# If the index is out of bounds, throw an exception, as below
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if index < 0 or index >= self._size:
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raise IndexError("Index out of bounds")
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return self._arr[index]
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def set(self, num: int, index: int):
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"""Update element"""
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if index < 0 or index >= self._size:
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raise IndexError("Index out of bounds")
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self._arr[index] = num
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def add(self, num: int):
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"""Add element at the end"""
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# When the number of elements exceeds capacity, trigger the expansion mechanism
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if self.size() == self.capacity():
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self.extend_capacity()
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self._arr[self._size] = num
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self._size += 1
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def insert(self, num: int, index: int):
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"""Insert element in the middle"""
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if index < 0 or index >= self._size:
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raise IndexError("Index out of bounds")
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# When the number of elements exceeds capacity, trigger the expansion mechanism
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if self._size == self.capacity():
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self.extend_capacity()
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# Move all elements after `index` one position backward
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for j in range(self._size - 1, index - 1, -1):
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self._arr[j + 1] = self._arr[j]
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self._arr[index] = num
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# Update the number of elements
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self._size += 1
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def remove(self, index: int) -> int:
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"""Remove element"""
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if index < 0 or index >= self._size:
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raise IndexError("Index out of bounds")
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num = self._arr[index]
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# Move all elements after `index` one position forward
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for j in range(index, self._size - 1):
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self._arr[j] = self._arr[j + 1]
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# Update the number of elements
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self._size -= 1
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# Return the removed element
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return num
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def extend_capacity(self):
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"""Extend list"""
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# Create a new array of _extend_ratio times the length of the original array and copy the original array to the new array
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self._arr = self._arr + [0] * self.capacity() * (self._extend_ratio - 1)
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# Update list capacity
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self._capacity = len(self._arr)
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def to_array(self) -> list[int]:
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"""Return a list of valid lengths"""
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return self._arr[: self._size]
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"""Driver Code"""
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if __name__ == "__main__":
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# Initialize list
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nums = MyList()
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# Add element at the end
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nums.add(1)
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nums.add(3)
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nums.add(2)
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nums.add(5)
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nums.add(4)
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print(f"List nums = {nums.to_array()} ，capacity = {nums.capacity()} ，length = {nums.size()}")
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# Insert element in the middle
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nums.insert(6, index=3)
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print("Insert number 6 at index 3, resulting in nums =", nums.to_array())
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# Remove element
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nums.remove(3)
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print("Remove the element at index 3, resulting in nums =", nums.to_array())
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# Access element
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num = nums.get(1)
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print("Access the element at index 1, resulting in num =", num)
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# Update element
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nums.set(0, 1)
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print("Update the element at index 1 to 0, resulting in nums =", nums.to_array())
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# Test expansion mechanism
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for i in range(10):
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# At i = 5, the list length will exceed the list capacity, triggering the expansion mechanism at this time
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nums.add(i)
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print(f"After expansion, the list {nums.to_array()} ，capacity = {nums.capacity()} ，length = {nums.size()}")
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