Subsets 2 solution

Author: joshguha

90_subsets_2.py

@@ -0,0 +1,44 @@
+class Solution(object):
+    # def subsetsWithDup(self, nums):
+    #     """
+    #     :type nums: List[int]
+    #     :rtype: List[List[int]]
+    #     """
+    #     nums.sort()
+    #     res = []
+    #     for i in range(1 << len(nums)):
+    #         res.append(self.get_subsets(nums, i))
+    #     # remove duplicate
+    #     final_res = {}
+    #     for subset in res:
+    #         hash_key = ''.join([str(t) for t in subset])
+    #         try:
+    #             final_res[hash_key]
+    #         except:
+    #             final_res[hash_key] = subset
+    #     return final_res.values()
+    #
+    # def get_subsets(self, nums, magic):
+    #     res = []
+    #     for i in range(len(nums)):
+    #         if (1 << i) & magic != 0:
+    #             res.append(nums[i])
+    #     return res
+
+    def subsetsWithDup(self, nums):
+        nums.sort()
+        res = [[]]
+        begin = 0
+        for index in range(len(nums)):
+            if index == 0 or nums[index] != nums[index - 1]:
+                # generate all
+                begin = 0
+            size = len(res)
+            # use existing subsets to generate new subsets
+            for j in range(begin, size):
+                curr = list(res[j])
+                curr.append(nums[index])
+                res.append(curr)
+            # avoid duplicate subsets
+            begin = size
+        return res