1863.Sum of All Subset XOR Totals

Link: 1863. Sum of All Subset XOR Totals - Easy
Track: NeetCode150

Question

Restate the problem

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Method 1
Method 2

Method - DFS

Approach

• use backtracking to cal every possible solution
• Base case: if reach the end, complete one subset, add total into res
• At each index i, have two choices
  • pick: dfs(i+1, total ^ nums[i])
  • not pick: dfs(i+1, total)

Complexity

• Time Complexity: O($2^n$)
• Space Complexity: O(n)

Edge Case

Code

class Solution:
    def subsetXORSum(self, nums: List[int]) -> int:
        self.ans = 0
        n = len(nums)
        def dfs(start, total):
            if start == n:
                self.ans += total
                return
            
            dfs(start + 1, total ^ nums[start])
            dfs(start + 1, total)
 
        dfs(0, 0)
        return self.ans

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History

Jan-21-2026 Peeked

• XOR is ^