Explain the concept of code duplication and its relation to program complexity.

Code duplication refers to the presence of identical or similar code segments in different parts of a program. It occurs when developers copy and paste code instead of creating reusable functions or modules. Code duplication can lead to increased program complexity for several reasons.

Firstly, code duplication makes the program harder to understand and maintain. When the same logic is repeated in multiple places, it becomes difficult to track and update. Any changes or bug fixes need to be applied to each duplicated segment, increasing the chances of introducing errors or inconsistencies. This can result in a higher maintenance cost and reduced productivity for developers.

Secondly, code duplication violates the principle of Don't Repeat Yourself (DRY). DRY is a software development principle that promotes code reuse and modularity. By duplicating code, we are essentially violating this principle and creating unnecessary redundancy. This redundancy not only increases the size of the codebase but also makes it more error-prone and difficult to maintain.

Furthermore, code duplication can lead to a higher cognitive load for developers. When encountering duplicated code, developers need to remember and understand its purpose and behavior in multiple contexts. This cognitive overhead can slow down the development process and increase the likelihood of introducing bugs.

In terms of program complexity, code duplication contributes to a higher cyclomatic complexity. Cyclomatic complexity is a metric that measures the number of independent paths through a program's source code. When code is duplicated, the number of paths increases, leading to a higher cyclomatic complexity. Higher cyclomatic complexity indicates a higher probability of bugs and makes the program more difficult to test and analyze.

To mitigate the negative impact of code duplication on program complexity, developers should strive to refactor duplicated code into reusable functions or modules. By creating abstractions and promoting code reuse, the complexity of the program can be reduced, making it easier to understand, maintain, and test.