Which approach guarantees generating all unique subsets efficiently without redundant computations?
easy🔍 Pattern Recognition Q11 of Q15
Subsets & Combinations - Subsets II (With Duplicates)
You are given an integer array that may contain duplicates. Your task is to find all possible subsets without duplicate subsets in the result. Which approach guarantees generating all unique subsets efficiently without redundant computations?
AGenerate all subsets using brute force recursion and then filter duplicates by storing subsets in a hash set.
BUse a greedy algorithm that picks elements only if they are not duplicates of the previous element.
CUse dynamic programming with a 2D table tracking subset sums to avoid duplicates.
DSort the array and use backtracking with skipping duplicates at the same recursion depth to avoid repeated subsets.
Step-by-Step Solution
Solution:
Step 1: Understand the problem constraints
The problem requires generating all unique subsets from an array that may contain duplicates, avoiding duplicate subsets in the output.
Step 2: Identify the approach that handles duplicates efficiently
Sorting the array groups duplicates together, allowing the backtracking algorithm to skip duplicates at the same recursion level, preventing repeated subsets without extra filtering.
Final Answer:
Option D -> Option D
Quick Check:
Backtracking with sorting and skipping duplicates is the standard pattern for Subsets II [OK]
Quick Trick:Sort and skip duplicates at recursion level [OK]
Common Mistakes:
MISTAKES
Using greedy approach misses some subsets
DP approach is unrelated to subset generation here
Brute force with set filtering is inefficient
Trap Explanation:
PITFALL
Brute force with set filtering looks correct but is inefficient; greedy misses subsets; DP is unrelated here.
Interviewer Note:
CONTEXT
Tests if candidate recognizes the canonical pattern for subsets with duplicates.
Master "Subsets II (With Duplicates)" in Subsets & Combinations
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