78. Subsets 与90. Subsets II

Given a set of distinct integers, nums, return all possible subsets (the power set).

Note: The solution set must not contain duplicate subsets.

Example:

Input: nums = [1,2,3]
Output:
[
  [3],
  [1],
  [2],
  [1,2,3],
  [1,3],
  [2,3],
  [1,2],
  []
]

题目大意:输出一个list的全部子数组

思路:遍历数据:第一次是空[[]],第二次把第一次的空加上一个元素,和上一次的合并一起[[],[1]],重复执行上面操作,[[],[1],[2],[1,2]].....

class Solution(object):
    def subsets(self, nums):
        """
        :type nums: List[int]
        :rtype: List[List[int]]
        """
        
        res=[[]]
        
        for i in nums:
            temp=[]
            for j in res:
                temp.append(j+[i])
            res+=(temp)     
        return res

Given a collection of integers that might contain duplicates, nums, return all possible subsets (the power set).

Note: The solution set must not contain duplicate subsets.

Example:

Input: [1,2,2]
Output:
[
  [2],
  [1],
  [1,2,2],
  [2,2],
  [1,2],
  []
]

题意:如果有重复,去除重复的

解法:给每个排序,判断是否已经在其中

class Solution(object):
    def subsetsWithDup(self, nums):
        """
        :type nums: List[int]
        :rtype: List[List[int]]
        """
        result=[[]]
        #result_set=set()
        for i in nums:
            temp=[]
            temp_set=[]
            for j in result:
                temp_temp=j+[i]
                temp_temp=sorted(temp_temp)
                if(temp_temp in temp or temp_temp in result):
                    continue
                temp.append(temp_temp)
            #print(temp)
            result+=temp
        return result
            
        

 

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