What is a 3 sum?

The 3-sum problem is a classic computational problem in computer science and mathematics, where the goal is to determine if there are three distinct numbers in a given set that sum up to a specific target value, typically zero. It is often used to illustrate concepts in algorithm design, particularly in relation to complexity and optimization. The problem can be solved using various approaches, including brute-force methods and more efficient algorithms like sorting combined with the two-pointer technique.