Comparison of Methods

Key Concepts of C Used in Above Programs

Input/Output in C: Using printf() and scanf() for user interaction.
Arithmetic Operators in C: Adding numbers and applying the summation formula.
Loops in C: Using for and while loops for iterative summation.
Functions in C: Encapsulating summation logic in reusable functions.
Recursion in C: Calculating the sum by breaking the problem into smaller subproblems.
Conditional Statements in C: Handling edge cases, such as n=0.
Efficient Memory Usage: Avoiding excessive resource usage in iterative and formula-based methods.