Can I use Python/Java/C++ for Lexicographically Largest String After Pair Transformations?

Yes, FleetCode supports multiple languages including Python, Java, and C++. The greedy solution can be implemented in any language using an array of size 26 for character mapping.

What is the best approach for Lexicographically Largest String After Pair Transformations?

The best approach is a greedy algorithm that processes the string from left to right, applying the transformation that yields the largest possible character at each position. This works because lexicographic order is determined by the earliest differing character, and transformations are independent. It runs in O(n + m) time and O(1) space.

Is Lexicographically Largest String After Pair Transformations asked at Google/Amazon/Meta?

While not confirmed for specific companies, this problem tests greedy algorithms and string manipulation, which are common topics in technical interviews at top companies like Google, Amazon, and Meta. Practicing such problems helps build skills for similar interview questions.

What data structure is used in Lexicographically Largest String After Pair Transformations?

The optimal solution uses a fixed-size array (or hash map) of size 26 to store either the frequency of available transformations or the best mapping for each character. This provides O(1) lookup and update operations.

What is the time complexity of Lexicographically Largest String After Pair Transformations?

The optimal greedy solution runs in O(n + m) time, where n is the length of the string and m is the number of transformations. Space complexity is O(1) because you only store a fixed-size frequency array or mapping.

4036. Lexicographically Largest String After Pair Transformations - Practice Online

Q: Is Lexicographically Largest String After Pair Transformations easy or hard?

It's rated Medium on FleetCode with a 39.7% acceptance rate. The brute force approach is easy to understand but exponential, while the optimal greedy solution requires insight into lexicographic ordering and transformation independence.

Q: How to solve Lexicographically Largest String After Pair Transformations in O(n)?

You can solve it in O(n + m) by precomputing for each character the maximum character it can become using any transformation. Then iterate through the string and replace each character with its precomputed maximum if it's larger. This avoids checking all transformations for each position.

You are given an integer array nums.

For each integer x in nums, start with a string consisting of exactly x lowercase 'a' characters.

You may perform the following operation any number of times (including zero):

Choose two adjacent equal letters and replace them with the next letter in the alphabet.

For example, "aa" can be replaced with "b", and "bb" can be replaced with "c". The pair "zz" cannot be replaced.

For each x, determine the lexicographically largest string that can be obtained.

Return an array of strings where the i^th string is the answer for nums[i].

A string a is lexicographically larger than a string b if, at the first position where they differ, a contains a letter that appears later in the alphabet than the corresponding letter in b. If the first min(a.length, b.length) characters are equal, the longer string is lexicographically larger.

Example 1:

Input: nums = [2,5,7]

Output: ["b","ca","cba"]

Explanation:

nums[0] = 2: "aa" → "b".
nums[1] = 5: "aaaaa" → "baaa" → "bba" → "ca".
nums[2] = 7: "aaaaaaa" → "baaaaa" → "bbaaa" → "bbba" → "cba".
Therefore, ans = ["b", "ca", "cba"].

Example 2:

Input: nums = [3,9,1]

Output: ["ba","da","a"]

Explanation:

nums[0] = 3: "aaa" → "ba".
nums[1] = 9: "aaaaaaaaa" → "baaaaaaa" → "bbaaaaa" → "bbbaaa" → "bbbba" → "cbba" → "cca" → "da".
nums[2] = 1: No transformation can be applied, so the result is "a".
Therefore, ans = ["ba", "da", "a"].

Constraints:

1 <= nums.length <= 10⁵
1 <= nums[i] <= 10⁸