Recursion

Hi hello ,
Im just new to c++
and im using turbo c++ 4.5 or borland c++ 4.5
as i want to learn first the old one before the new one ( i dont know why)
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Now I'm Making Trouble with this Project of mine
Using Recursion to find the sum of 10 numbers
e.g: 1+2+3+4+5+6+7+8+9+10 = 55
i can only make iterative using looping statements.
I dont know recursion please help? Thanks in advance! :)
Merry Christmas and Happy New Year! :)
The trick to understanding recursion is that you must first understand recursion.
Uhm Can you Show me some codes of it?
Not all just a bit so i can understand the Logic behind it? :)
Thanks :)
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#include <iostream>

int Factorial(int n) {
   if (n > 1)
      return n * Factorial (n - 1);
   else
      return 1;
}

int main() {
   int n = 5;

   std::cout << n << "! = " << Factorial(n);

   return 0;
}
5! = 120
In fact iteration is the same as recursion but has a condensed form.:)
If you emulate the stack...

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void paint(int row, int col, int key, int colour){ //key not_eq colour
   if( map[row][col] not_eq key ) //base case (centinels
      return;
   map[row][col] = colour;

   //recursion
   paint(row+1, col, key, colour);
   paint(row, col+1, key, colour);
   paint(row-1, col, key, colour);
   paint(row, col-1, key, colour);
}

Now suppose that the recursive calls does execute simultaneously.*
The order would be O( lg n ).

* By instance the processor is a bacteria, at the recursion point it performs mitosis.


Edit: changed the example
Last edited on
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