1400. Construct K Palindrome Strings

Given a string s and an integer k, return true if you can use all the characters in s to construct k palindrome strings or false otherwise.

1328. Break a Palindrome

Given a palindromic string of lowercase English letters palindrome, replace exactly one character with any lowercase English letter so that the resulting string is not a palindrome and that it is the lexicographically smallest one possible.

Return the resulting string. If there is no way to replace a character to make it not a palindrome, return an empty string.

A string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, a has a character strictly smaller than the corresponding character in b. For example, “abcc” is lexicographically smaller than “abcd” because the first position they differ is at the fourth character, and ‘c’ is smaller than ‘d’.

1239. Maximum Length of a Concatenated String with Unique Characters

You are given an array of strings arr. A string s is formed by the concatenation of a subsequence of arr that has unique characters.

Return the maximum possible length of s.

A subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.

1405. Longest Happy String

A string s is called happy if it satisfies the following conditions:

• s only contains the letters ‘a’, ‘b’, and ‘c’.
• s does not contain any of “aaa”, “bbb”, or “ccc” as a substring.
• s contains at most a occurrences of the letter ‘a’.
• s contains at most b occurrences of the letter ‘b’.
• s contains at most c occurrences of the letter ‘c’.

Given three integers a, b, and c, return the longest possible happy string. If there are multiple longest happy strings, return any of them. If there is no such string, return the empty string “”.

A substring is a contiguous sequence of characters within a string.

548. Split Array with Equal Sum

Given an integer array nums of length n, return true if there is a triplet (i, j, k) which satisfies the following conditions:

• 0 < i, i + 1 < j, j + 1 < k < n - 1
• The sum of subarrays (0, i - 1), (i + 1, j - 1), (j + 1, k - 1) and (k + 1, n - 1) is equal.

A subarray (l, r) represents a slice of the original array starting from the element indexed l to the element indexed r.

1707. Maximum XOR With an Element From Array

You are given an array nums consisting of non-negative integers. You are also given a queries array, where queries[i] = [xi, mi].

The answer to the ith query is the maximum bitwise XOR value of xi and any element of nums that does not exceed mi. In other words, the answer is max(nums[j] XOR xi) for all j such that nums[j] <= mi. If all elements in nums are larger than mi, then the answer is -1.

Return an integer array answer where answer.length == queries.length and answer[i] is the answer to the ith query.

1223. Dice Roll Simulation

A die simulator generates a random number from 1 to 6 for each roll. You introduced a constraint to the generator such that it cannot roll the number i more than rollMax[i] (1-indexed) consecutive times.

Given an array of integers rollMax and an integer n, return the number of distinct sequences that can be obtained with exact n rolls. Since the answer may be too large, return it modulo 109 + 7.

Two sequences are considered different if at least one element differs from each other.

1723. Find Minimum Time to Finish All Jobs

You are given an integer array jobs, where jobs[i] is the amount of time it takes to complete the ith job.

There are k workers that you can assign jobs to. Each job should be assigned to exactly one worker. The working time of a worker is the sum of the time it takes to complete all jobs assigned to them. Your goal is to devise an optimal assignment such that the maximum working time of any worker is minimized.

Return the minimum possible maximum working time of any assignment.

1163. Last Substring in Lexicographical Order

Given a string s, return the last substring of s in lexicographical order.

1665. Minimum Initial Energy to Finish Tasks

You are given an array tasks where tasks[i] = [actuali, minimumi]:

• actuali is the actual amount of energy you spend to finish the ith task.
• minimumi is the minimum amount of energy you require to begin the ith task.

For example, if the task is [10, 12] and your current energy is 11, you cannot start this task. However, if your current energy is 13, you can complete this task, and your energy will be 3 after finishing it.

You can finish the tasks in any order you like.

Return the minimum initial amount of energy you will need to finish all the tasks.