leetcode 47. 全排列 II 48. 组合总和 II
47. 全排列 II
难度中等865收藏分享切换为英文接收动态反馈
给定一个可包含重复数字的序列 nums ，按任意顺序 返回所有不重复的全排列。
示例 1：
输入：nums = [1,1,2]
输出：
[[1,1,2],
[1,2,1],
[2,1,1]]示例 2：
输入：nums = [1,2,3]
输出：[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]提示：
1 <= nums.length <= 8-10 <= nums[i] <= 10
通过次数231,822
提交次数362,400
# leetcode submit region begin(Prohibit modification and deletion)
from typing import List
class Solution:
def permuteUnique(self, nums: List[int]) -> List[List[int]]:
def dfs(nums: List[int]):
arr = []
if len(nums) == 2:
if nums[0] != nums[1]:
return [[nums[0], nums[1]], [nums[1], nums[0]]]
return [nums]
keys = []
for i in range(len(nums)):
if nums[i] in keys:
continue
nums2 = nums.copy()
keys.append(nums[i])
del nums2[i]
r = dfs(nums2)
for k in r:
k.insert(0, nums[i])
arr.append(k)
return arr
if len(nums) < 2:
return [nums]
return dfs(nums)
def permuteUnique2(self, nums: List[int]) -> List[List[int]]:
def dfs(nums: List[int]):
arr = []
if len(nums) == 2:
if nums[0] != nums[1]:
return [[nums[0], nums[1]], [nums[1], nums[0]]]
return [nums]
for i in range(len(nums)):
nums2 = nums.copy()
del nums2[i]
r = dfs(nums2)
for k in r:
k.insert(0, nums[i])
if k not in arr:
arr.append(k)
return arr
if len(nums) < 2:
return [nums]
return dfs(nums)
# leetcode submit region end(Prohibit modification and deletion)
if __name__ == '__main__':
nums = [1, 1, 2]
# nums = [1, 1]
print(Solution().permuteUnique(nums))48. 旋转图像
难度中等1059收藏分享切换为英文接收动态反馈
给定一个 n × n 的二维矩阵 matrix 表示一个图像。请你将图像顺时针旋转 90 度。
你必须在** 原地** 旋转图像，这意味着你需要直接修改输入的二维矩阵。请不要 使用另一个矩阵来旋转图像。
示例 1：
输入：matrix = [[1,2,3],[4,5,6],[7,8,9]]
输出：[[7,4,1],[8,5,2],[9,6,3]]示例 2：
输入：matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
输出：[[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]示例 3：
输入：matrix = [[1]]
输出：[[1]]示例 4：
输入：matrix = [[1,2],[3,4]]
输出：[[3,1],[4,2]]提示：
matrix.length == nmatrix[i].length == n1 <= n <= 20-1000 <= matrix[i][j] <= 1000
# leetcode submit region begin(Prohibit modification and deletion)
from typing import List
class Solution:
def rotate(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
length = len(matrix) - 1
for i in range((length + 1) // 2):
for j in range(i,length - i):
# tmp = matrix[i][j]
matrix[i][j], matrix[length - j][i], matrix[length - i][length - j], matrix[j][length - i] = \
matrix[length - j][i], matrix[length - i][length - j], matrix[j][length - i], matrix[i][j]
# matrix[i][j] = matrix[length - j][i]
# matrix[length - j][i] = matrix[length - i][length - j]
# matrix[length - i][length - j] = matrix[j][length - i]
# matrix[j][length - i] = tmp
return matrix
def rotate2(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
length = len(matrix)
a = [[0 for _ in range(length)] for _ in range(length)]
for j in range(length):
for k in range(length):
a[k][length - 1 - j] = matrix[j][k]
matrix[:] = a
def rotate3(self, matrix: List[List[int]]) -> None:
n = len(matrix)
# 水平翻转
for i in range(n // 2):
for j in range(n):
matrix[i][j], matrix[n - i - 1][j] = matrix[n - i - 1][j], matrix[i][j]
# 主对角线翻转
for i in range(n):
for j in range(i):
matrix[i][j], matrix[j][i] = matrix[j][i], matrix[i][j]
# leetcode submit region end(Prohibit modification and deletion)
if __name__ == '__main__':
matrix = [[1,2,3],[4,5,6],[7,8,9]]
matrix = [[5, 1, 9, 11], [2, 4, 8, 10], [13, 3, 6, 7], [15, 14, 12, 16]]
print(Solution().rotate(matrix))
deletion)
if __name__ == '__main__':
matrix = [[1,2,3],[4,5,6],[7,8,9]]
matrix = [[5, 1, 9, 11], [2, 4, 8, 10], [13, 3, 6, 7], [15, 14, 12, 16]]
print(Solution().rotate(matrix))
