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First, the basic content:
Functions in the C language can be called recursively, that is, you can adjust yourself directly (simply recursively) or indirectly (indirectly recursively).Points:1, C language functions can be invoked recursively.2. Can be called directly or indirectly by two ways. Only direct recursive calls are currently discussed.
Second, recursive conditions
The following three conditions
, 5)===> 120At the end of a recursive call, if optimized, the stack does not grow, so no amount of calls will cause the stack to overflow.Unfortunately, most programming languages are not optimized for tail recursion, and the Python interpreter is not optimized, so even if the above function is changed to fact(n) tail recursion, it can cause the stack to overflow
; fact_iter(4, 5)===> fact_iter(3, 20)===> fact_iter(2, 60)===> fact_iter(1, 120)===> 120At the end of a recursive call, if optimized, the stack does not grow, so no amount of calls will cause the stack to overflow.Unfortunately, most programming languages are not optimized for tail recursion, and the Python interpreter is not optimized, so even if the above function
始做包子啦‘)foriinrange(10):time.sleep(1)print(‘%s 做了两个包子‘%name)C.send(i)C1.send(i)producer(‘test‘)
Adorner:Python decorator see another piece of documentation.RecursiveCharacteristicsRecursive algorithm is a direct or indirect process of invoking its own method, it often makes the description of the algorithm and easy to understand.The recursive algorithm solves the problem with the following characteristics:(1) Recursion is the invocation of itse
Recursive definition-- call the function itself in a functionNow we probably know what the story function has just been doing, which is to call the function itself in a function , and this magic way of using the function is called
Select Name,age from staff_table where age > 22
SELECT * from staff_table where dept = "IT"
SELECT * from staff_table where enroll_date like "2013"
Find the information, after printing, the last side to show the number of found
Can create a new employee record, with the phone to do unique keys, staff_id need to increase
Delete a specified employee information record, enter an employee ID, and delete
To modify employee information, the syntax is as
repetitions, the previous one to be prepared for the next (usually the previous output as the last input).③ must use direct contact solution instead of recursive invocation when the scale of the problem is minimal, so that each recursive invocation is conditional (with the size not reaching the direct solution),An unconditional recursive call will become a dead
recursive function. # tail recursion means that when a function returns, it calls itself, and the return statement cannot contain an expression # so that the compiler or interpreter can optimize the tail recursion, so that the recursion itself no matter how many times it is called, All occupy only one stack frame, there is no stack overflow situation # above the
This article gives you a detailed explanation of the decorator and recursive algorithm in python. If you need it, you can refer to it. I hope it will help you learn Python.
1. python decorators
I just got in touch with the python decorator, and I just forgot how many times
First, the definition of recursionA recursive call is a special form of a function nested call that invokes itself directly or indirectly when called, or recursively.second, recursion is divided into two stages: recursion, backtrackingAge (5) = Age (4) + 2age (4) = Age (3) + 2age (3) = Age (2) + 2age (2) = Age (1) + 2age (1) = 18age (n) =age (n-1) +2 #n >1age (1) =18 #n =1######################### #3def Age
X1=1/2 (x0+a/x0)For example, A is 2 o'clock, the square root value: 1.414214#include #include Double Fun (double A, dounle x0){double x1, y;x1= (x0+ a/x0)/2.0;if (Fabs (x1-x0) >=0.00001)Y=fun (A,X1);else y=x1;return y;}Main (){Double x;printf ("Enter x:"); scanf ("%lf", x);printf ("The square root of%lf is%lf\n", X,fun (x,1.0));}The function of function fun in a given program is to use
), you can achieve the purpose of timing, which is the concept of adorners, it looks like sum1 was Timeit decorated! Python then provides a syntactic sugar to reduce the amount of character input.
Import Time def Timeit (func): def Test (): start = Time.clock () func () end =time.clock () Print ("Time used:", End-start) return test @timeit def sum1 (): sum = 1+ 2 print (sum) sum1 ()
Focusing on the @timeit of line 11th, ad
This article mainly introduces the recursive use of Python in the end, the more detailed analysis of the tail recursion principle and related use skills, very practical value, the need for friends can refer to the
This example describes the recursive use of Python in the tail. Share to everyone for your reference. The
Python recursive functions and Examples
Python recursive functions
If a function body calls itself directly or indirectly, this function is called a recursive
)) ===> 5 * (4 * 6) ===> 5 * 24===> 120 The advantage of a recursive function is that the definition is simple and logically clear. In theory, all recursive functions can be written in a circular way, but the logic of the loop is not as clear as recursion. The use of recursive functions requires careful prevention of s
analysis of time complexity of recursive function
(1) Recursive execution processExample: Seek n!.This is a simple "tired multiply" problem, with recursive algorithm can also be solved.N!= n * (n-1)! n > 10!= 1, 1! = 1 N = 0,1Therefore, the recursive algorithm is as follows:
Python can call other functions inside the function, and if a function calls itself internally, the function is a recursive functionWrite a factorial recursive function def func(n):n =
PythonRecursive Functions detailed A function that calls the current function itself within a function is a recursive functionThe following is an example of a recursive function:The first time a person touches a recursive
The example in this paper describes the recursive use of the tail in Python. Share to everyone for your reference. The specific analysis is as follows:
If all the recursive calls in a function appear at the end of the function, we call this
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