You have a set of integers s, which originally contains all the numbers from 1 to n. Unfortunately, due to some error, one of the numbers in s got duplicated to another number in the set, which results in repetition of one number and loss of another number.

Alice has n candies, where the ith candy is of type candyType[i]. Alice noticed that she started to gain weight, so she visited a doctor.

Given a sorted array nums, remove the duplicates in-place such that each element appears only once and returns the new length.

Given the head of a linked list, remove the nth node from the end of the list and return its head.

Write a function to find the longest common prefix string amongst an array of strings.

SQL exercise from leetcode Database category at level of Easy and Medium

Singly-Linked List

9. Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

7. Given a 32-bit signed integer, reverse digits of an integer.

1. Given an array of integers, return indices of the two numbers such that they add up to a specific target.