Subsets ii

Array Backtracking Bit Manipulation

60.9% acceptance

Jan 12, 2026

10864

408

Given an integer array nums that may contain duplicates, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order.

Solution

Rust

Time O(n log n)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn subsets_with_dup(mut nums: Vec<i32>) -> Vec<Vec<i32>> {
    nums.sort();
    let mut result = Vec::new();
    let mut current = Vec::new();
    Self::backtrack(&nums, 0, &mut current, &mut result);
    result
  }
  
  fn backtrack(nums: &[i32], start: usize, current: &mut Vec<i32>, result: &mut Vec<Vec<i32>>) {
    result.push(current.clone());
    
    for i in start..nums.len() {
      if i > start && nums[i] == nums[i-1] {
        continue;
      }
      current.push(nums[i]);
      Self::backtrack(nums, i + 1, current, result);
      current.pop();
    }
  }
}