C + + iterative and recursive analysis

"What is recursion"

Recursion is called repeatedly by the function itself.

There are two points to note when using recursion:

1) recursion is the invocation of itself within a procedure or function;

2) When using recursion, there must be a definite recursive end condition called a recursive exit.

Recursion is divided into two stages:

1) Recursion: The solution of the complex problem is pushed to a simpler problem than the original problem;

2) Regression: When the simplest case is obtained, it is gradually returned and the complex solution is obtained in turn.

"What is Iteration"

Use the original value of the variable to derive a new value for the variable. If recursion calls itself by itself, the iteration is a non-stop call to B.

"The difference between recursion and iteration"

Recursion and function call itself; iteration is a loop, and there is a self-change in the loop body.

"Code parsing"

This is recursive  int Funca (int n)  {      if (n > 1)         return N+funca (n-1);      else          return 1;  }  This is the iteration  int FUNCB (int n)  {      int i,s=0;      for (i=1;i<n;i++)         s+=i;      return s;  }

here recursion, that is, Funa itself calls; The iteration here, that is, the FUNB constant cyclic invocation of s, makes s self-changing;

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

C + + iterative and recursive analysis