Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target

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

2. Given an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal's triangle.
In Pascal's triangle, each number is the sum of the two numbers directly above it as shown


3. Given n pairs of parentheses, write a function to generate all combinations of well-formed
parentheses