May 29, 2023 · May 25, 2023 · May 26, 2023 · May 26, 2023 · May 26, 2023 · May 26, 2023
diff --git a/problems/0046.全排列.md b/problems/0046.全排列.md
Original file line number	Diff line number	Diff line change
Expand Up		@@ -213,68 +213,27 @@ class Solution {
		```

		### Python
	回溯
	回溯使用used
		```python
		class Solution:
	def __init__(self):
	self.path = []
	self.paths = []

	def permute(self, nums: List[int]) -> List[List[int]]:
	'''
	因为本题排列是有序的,这意味着同一层的元素可以重复使用,但同一树枝上不能重复使用(usage_list)
	所以处理排列问题每层都需要从头搜索,故不再使用start_index
	'''
	usage_list = [False] * len(nums)
	self.backtracking(nums, usage_list)
	return self.paths

	def backtracking(self, nums: List[int], usage_list: List[bool]) -> None:
	# Base Case本题求叶子节点
	if len(self.path) == len(nums):
	self.paths.append(self.path[:])
	def permute(self, nums):
	result = []
	self.backtracking(nums, [], [False] * len(nums), result)
	return result

	def backtracking(self, nums, path, used, result):
	if len(path) == len(nums):
	result.append(path[:])
		return

	# 单层递归逻辑
	for i in range(0, len(nums)): # 从头开始搜索
	# 若遇到self.path里已收录的元素,跳过
	if usage_list[i] == True:
	for i in range(len(nums)):
	if used[i]:
		continue
	usage_list[i] = True
	self.path.append(nums[i])
	self.backtracking(nums, usage_list) # 纵向传递使用信息,去重
	self.path.pop()
	usage_list[i] = False
	```
	回溯+丢掉usage_list
	```python
	class Solution:
	def __init__(self):
	self.path = []
	self.paths = []

	def permute(self, nums: List[int]) -> List[List[int]]:
	'''
	因为本题排列是有序的,这意味着同一层的元素可以重复使用,但同一树枝上不能重复使用
	所以处理排列问题每层都需要从头搜索,故不再使用start_index
	'''
	self.backtracking(nums)
	return self.paths

	def backtracking(self, nums: List[int]) -> None:
	# Base Case本题求叶子节点
	if len(self.path) == len(nums):
	self.paths.append(self.path[:])
	return
	used[i] = True
	path.append(nums[i])
	self.backtracking(nums, path, used, result)
	path.pop()
	used[i] = False

	# 单层递归逻辑
	for i in range(0, len(nums)): # 从头开始搜索
	# 若遇到self.path里已收录的元素,跳过
	if nums[i] in self.path:
	continue
	self.path.append(nums[i])
	self.backtracking(nums)
	self.path.pop()
		```

		### Go
Expand Down