"Java" java_19 recursive algorithm

1. Recursive algorithm

A method called the B method, we are easy to understand! Recursion is:a method calls a Method! is to call yourself, so when designing a recursive algorithm, be sure to indicate when you don't call yourself. Otherwise, it's a dead loop!

1.1 main points of recursive algorithm

recursion is a common method of solving problems, which is to simplify the problem gradually. The basic idea of recursion is to " call yourself ", and a method that uses recursion technology will call itself directly or indirectly.

Recursion can be used to solve some complex problems with simple programs. For example: Most sorts use recursive algorithms.

1.2 Recursive structure

The recursive structure consists of two parts:

1. define the recursive header. Answer: When not to call its own method. If there is no head, it will fall into a dead loop.

2. recursive body. Answer: When to call your own method.

2. Code hinting

 Packagecom.oliver.test;
 Public classtestrecursion {Static intA = 0;  Public Static voidtest01 () {a++; System.out.println ("Recursive" +a+ "Times"); if(a<=10) {//Recursive Headertest01 (); }        Else{//Recursive bodySystem.out.println ("recursion ends! "); }    }         Public  Static inttest02 (intN) {        //Ask for factorial!         if(n==1){            return1; }        Else {            returnn*test02 (n-1); }            }     Public Static voidMain (string[] args) {//Call test01test01 (); intValue = test02 (3);    SYSTEM.OUT.PRINTLN ("Factorial result is:" +value); }}

3. Printing results

Recursion 1 times
Recursion 2 times
Recursion 3 times
Recursion 4 times
Recursion 5 times
Recursion 6 times
Recursion 7 times
Recursion 8 times
Recursion 9 times
Recursion 10 times
Recursion 11 times
Recursion ends!
Factorial results are: 6

"Java" java_19 recursive algorithm