Is Advantage Shuffle easy or hard?

Advantage Shuffle is rated Medium on LeetCode. The coding itself is straightforward once the greedy idea is clear, but recognizing the strategy of sacrificing smaller values and saving larger ones for winnable comparisons can take practice.

Advantage Shuffle Python/Java solution

Python implementations usually sort nums1 and use index sorting for nums2, then assign values with two pointers. Java solutions often use either the same greedy sorting approach or a TreeMap to perform ceiling lookups. Both achieve O(n log n) time and O(n) space.

How to solve Advantage Shuffle in O(n)?

A strict O(n) solution is not typical because sorting or ordered lookups are required to determine optimal pairings. The practical optimal solution is O(n log n) using sorting with a greedy two-pointer strategy. Any approach that needs ordering comparisons between elements generally requires sorting or balanced-tree operations.

What is the best approach for Advantage Shuffle?

The most common solution uses a greedy strategy with sorting and two pointers. Sort nums1 and process nums2 in descending order. If the largest remaining element in nums1 can beat the current nums2 value, assign it; otherwise sacrifice the smallest element. This runs in O(n log n) time due to sorting and uses O(n) space.

Is Advantage Shuffle asked at Google/Amazon/Meta?

Advantage Shuffle represents a common greedy matching pattern similar to problems asked at major tech companies including Google, Amazon, and Meta. Variants of this problem appear in interviews where candidates must maximize wins between two arrays using sorting and greedy decisions.

What data structure is used in Advantage Shuffle?

The main structures are arrays combined with sorting and two-pointer traversal. Some implementations also use ordered maps such as TreeMap or multiset structures to perform binary search for the smallest element greater than a target.

What is the time complexity of Advantage Shuffle?

Most optimal implementations run in O(n log n) time. The complexity comes from sorting one or both arrays or performing O(log n) ordered-map operations for each element. Space complexity is typically O(n) to store the result and auxiliary structures.

870. Advantage Shuffle - Practice Online

You are given two integer arrays nums1 and nums2 both of the same length. The advantage of nums1 with respect to nums2 is the number of indices i for which nums1[i] > nums2[i].

Return any permutation of nums1 that maximizes its advantage with respect to nums2.

Example 1:

Input: nums1 = [2,7,11,15], nums2 = [1,10,4,11]
Output: [2,11,7,15]

Example 2:

Input: nums1 = [12,24,8,32], nums2 = [13,25,32,11]
Output: [24,32,8,12]

Constraints:

1 <= nums1.length <= 10⁵
nums2.length == nums1.length
0 <= nums1[i], nums2[i] <= 10⁹