Define many-one function. Give an example of many-one functions.

In computer science and mathematics, a many-one function is a type of function that maps multiple input values to a single output value. In other words, it is a function where different input values can be mapped to the same output value. This is in contrast to a one-one function (also known as an injective function), where each input value is mapped to a unique output value.

An example of a many-one function is the modulus operator. The modulus operator (often denoted as %) computes the remainder when one number is divided by another. For example, if we consider the function f(x) = x % 5, where x is an integer, this function maps multiple input values to the same output value. For instance, f(2) = 2 % 5 = 2, f(7) = 7 % 5 = 2, and f(12) = 12 % 5 = 2. Here, different input values (2, 7, and 12) are all mapped to the same output value (2). Therefore, this function is a many-one function.