Find two numbers in a given array that add up to a specific target value, and return their indices. Essentially, you need to efficiently locate the pair that satisfies the sum requirement.

Given a string, find the most frequent character that appears earliest in the string. Return the length of the shortest substring that contains all occurrences of this character.

Given a sorted array, remove the duplicate elements in-place such that each unique element appears only once. Return the new length of the array.

Find the number of elements in an array that appear with the highest frequency. Essentially, count how many times the most frequent number occurs.

You're given daily stock prices. Find the maximum profit you can make by buying and selling the stock once. You must buy before you sell.

Given an array, rearrange it so that all zeros are moved to the end while maintaining the relative order of the non-zero elements.

Determine whether an integer is a palindrome. That is, it reads the same forwards and backward.

Find the length of the longest substring within a given string that contains no repeating characters. The substring must be contiguous.

Find the longest string that is a prefix of all strings in a given array. If no common prefix exists, return an empty string.

You're given two sorted lists. Combine them into a single sorted list containing all elements from both original lists.

Given an array, rotate the elements to the right by a specified number of steps. The goal is to modify the original array in-place with the rotated elements.

Given a sorted array, find the first and last position of a given target value. If the target is not found, return [-1, -1].

Construct the longest possible string using limited quantities of 'a', 'b', and 'c', ensuring that no three consecutive characters are the same. Return the longest string satisfying this constraint.

You are given two linked lists, each representing a non-negative integer. Add the two numbers and return the sum as a linked list.

Determine if a string containing parentheses is valid. A valid string has matching and properly nested opening and closing parentheses.

Given a set of coin denominations and a target amount, find the minimum number of coins needed to reach that amount. You can assume you have an unlimited supply of each coin type.

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. These consecutive numbers do not need to be adjacent in the original array.

Find the median of two sorted arrays. The arrays can be of different sizes, and you should aim for an efficient solution.

Given an array representing the height of bars, calculate how much water can be trapped between them after rain. Think about finding the maximum height to the left and right of each bar.

You're given an array containing only 0s, 1s, and 2s. Sort the array in place so that elements of the same value are grouped together.