Function and Recursion

Function is a module that has various kinds of commands in it, we can call the function if and only if the function is above the caller function.


Recursion is the application of a function that calls itself, is like a loop (while) but its work is heavier than looping, based on the base case and best case.

Advantages of using Functions:

• Top-down design with sub goal, huge program divided into smaller modules
• Can be done by more than one developer/ programmer
• Easier to debug, as logical flow is easy to follow and easier to pin point errors
• Modification can be done without affecting overall codes
• Easier to document

The library that we included in C are called functions as well, stdio.h, math.h. They have pre-built functions that we just need to call.

Example of function:

#include

int maximum (int x, int y){

      int max = x;

      if ( y > max) max = y;

      return max

}

void main () {

     int a,b;

     printf("Input 2 even values : ");

     scanf("%d %d", &a, &b);

     printf("Largest value : %d\n",maximum(a,b));

}

The recursive function consists of two components:

Base Case:

Return value (constant) without calling the next recursive call.

Reduction step:

Sequence of the input value that corresponds to the base case.

Example of recursion:

Factorial - Recursive

long factor (int n) 

{

    if(n==0) return (1); <<<<<Base case

      else return(n * factor(n-1));<<<< Reduction Step

}

Although recursive code is more concise it needs more memory consumption and takes longer time.

By :Steven
2201852132
Computer Science and Statistics