C Functions Practice Problems (original) (raw)
Last Updated : 08 Apr, 2025
**Functions are the basic building block of C programs. They enhance the modularity and code reusability by separating the logic of a particular task from the main code and using it whenever required. Functions are extensively used in almost all programs, so it is best for programmers to be familiar in using it.
Solving practice problems is the best way to improve your understanding. This article lists a variety of problems based on function concepts such as function definition, return type and parameters, recursion, etc. The list starts with easy problems which gets more difficult as we go down the list.
- Print Hello using Function
- Function to Print Sum
- Function to Return Sum
- Factorial (Using Function)
- Prime Factorization
- Table Difference
- Decimal to Binary
- Binary to Decimal
- Digital Root
- Sum of Digits of a Number
- Fibonacci Using Recursion
Prerequisite
The above problems mainly focus on the C functions, but they also require the knowledge of other basic concepts that are listed below:
- Input/Output
- Data Types and Variables
- Operators
- Control Statements
- Functions
- Recursion
If you have some doubts about these concepts, you can revise them from GeeksforGeeks' C Tutorial.
How to solve practice problems?
Each of the above link will take you to the practice portal where the problem statement tells you all the required information about the problem, and you have to write the solution in the code editor.
Once your solution is complete, you can check it for example test case using the **compile and run button at the bottom right of the page.
If you are sure of your solution, press the **submit button. The GfG's compiler will run your solution for a variety of test cases and if all these cases are passed, you solution will be accepted.
Your own custom cases can also be checked before submission by using **Custom Input button but keep in mind to follow the program's input layout.