Home Java javaTutorial Example code sharing about non-recursive traversal of binary trees

Example code sharing about non-recursive traversal of binary trees

Jul 18, 2017 pm 05:56 PM
recursion Traverse

What is the non-recursive traversal of a binary tree? Non-recursive traversal of binary trees also uses recursive ideas. Take preorder traversal as an example: first find the node in the lower left corner, then output it, and then perform the next operation on the right subtree of this node.

Pre-order traversal:

 public void pre_iteration(Node p) {if (p == null) return;
        Stack<Node> stack = new Stack<>();while (!stack.isEmpty() || p != null) {while (p != null) {
                System.out.println(p.val);
                stack.push(p);
                p = p.left;
            }if (!stack.isEmpty()) {
                p = stack.pop();
                p = p.right;
            }
        }
    }
Copy after login

Mid-order traversal:

public void in_iteration(Node p) {if (p == null) return;
        Stack<Node> stack = new Stack<>();while (!stack.isEmpty() || p != null) {while (p != null) {
                stack.push(p);
                p = p.left;
            }if (!stack.isEmpty()) {
                p = stack.pop();
                System.out.println(p.val);
                p = p.right;
            }
        }
    }
Copy after login

Post-order traversal: (stack2 is used to record Whether the right subtree of the current node has been traversed)

public static void post_iteration(Node p) {if (p == null) return;
        Stack<Node> stack = new Stack<>();
        Stack<Boolean> stack2 = new Stack<>();while (!stack.isEmpty() || p != null) {while (p != null) {
                stack.push(p);
                stack2.push(false);
                p = p.left;
            }while (!stack.isEmpty() && stack2.peek()) {
                System.out.println(stack.pop().val);
                stack2.pop();
            }if (!stack.isEmpty()) {
                p = stack.peek().right;
                stack2.pop();
                stack2.push(true);
            }
        }
    }
Copy after login

The above is the detailed content of Example code sharing about non-recursive traversal of binary trees. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1655
14
PHP Tutorial
1253
29
C# Tutorial
1227
24
Recursive implementation of C++ functions: Is there a limit to recursion depth? Recursive implementation of C++ functions: Is there a limit to recursion depth? Apr 23, 2024 am 09:30 AM

The recursion depth of C++ functions is limited, and exceeding this limit will result in a stack overflow error. The limit value varies between systems and compilers, but is usually between 1,000 and 10,000. Solutions include: 1. Tail recursion optimization; 2. Tail call; 3. Iterative implementation.

Do C++ lambda expressions support recursion? Do C++ lambda expressions support recursion? Apr 17, 2024 pm 09:06 PM

Yes, C++ Lambda expressions can support recursion by using std::function: Use std::function to capture a reference to a Lambda expression. With a captured reference, a Lambda expression can call itself recursively.

Count the number of occurrences of a substring recursively in Java Count the number of occurrences of a substring recursively in Java Sep 17, 2023 pm 07:49 PM

Given two strings str_1 and str_2. The goal is to count the number of occurrences of substring str2 in string str1 using a recursive procedure. A recursive function is a function that calls itself within its definition. If str1 is "Iknowthatyouknowthatiknow" and str2 is "know" the number of occurrences is -3. Let us understand through examples. For example, input str1="TPisTPareTPamTP", str2="TP"; output Countofoccurrencesofasubstringrecursi

Recursive implementation of C++ functions: Comparative analysis of recursive and non-recursive algorithms? Recursive implementation of C++ functions: Comparative analysis of recursive and non-recursive algorithms? Apr 22, 2024 pm 03:18 PM

The recursive algorithm solves structured problems through function self-calling. The advantage is that it is simple and easy to understand, but the disadvantage is that it is less efficient and may cause stack overflow. The non-recursive algorithm avoids recursion by explicitly managing the stack data structure. The advantage is that it is more efficient and avoids the stack. Overflow, the disadvantage is that the code may be more complex. The choice of recursive or non-recursive depends on the problem and the specific constraints of the implementation.

Java how to loop through a folder and get all file names Java how to loop through a folder and get all file names Mar 29, 2024 pm 01:24 PM

Java is a popular programming language with powerful file handling capabilities. In Java, traversing a folder and getting all file names is a common operation, which can help us quickly locate and process files in a specific directory. This article will introduce how to implement a method of traversing a folder and getting all file names in Java, and provide specific code examples. 1. Use the recursive method to traverse the folder. We can use the recursive method to traverse the folder. The recursive method is a way of calling itself, which can effectively traverse the folder.

C++ Recursion Advanced: Understanding Tail Recursion Optimization and Its Application C++ Recursion Advanced: Understanding Tail Recursion Optimization and Its Application Apr 30, 2024 am 10:45 AM

Tail recursion optimization (TRO) improves the efficiency of certain recursive calls. It converts tail-recursive calls into jump instructions and saves the context state in registers instead of on the stack, thereby eliminating extra calls and return operations to the stack and improving algorithm efficiency. Using TRO, we can optimize tail recursive functions (such as factorial calculations). By replacing the tail recursive call with a goto statement, the compiler will convert the goto jump into TRO and optimize the execution of the recursive algorithm.

Detailed explanation of C++ function recursion: application of recursion in string processing Detailed explanation of C++ function recursion: application of recursion in string processing Apr 30, 2024 am 10:30 AM

A recursive function is a technique that calls itself repeatedly to solve a problem in string processing. It requires a termination condition to prevent infinite recursion. Recursion is widely used in operations such as string reversal and palindrome checking.

Detailed explanation of C++ function recursion: tail recursion optimization Detailed explanation of C++ function recursion: tail recursion optimization May 03, 2024 pm 04:42 PM

Recursive definition and optimization: Recursive: A function calls itself internally to solve difficult problems that can be decomposed into smaller sub-problems. Tail recursion: The function performs all calculations before making a recursive call, which can be optimized into a loop. Tail recursion optimization condition: recursive call is the last operation. The recursive call parameters are the same as the original call parameters. Practical example: Calculate factorial: The auxiliary function factorial_helper implements tail recursion optimization, eliminates the call stack, and improves efficiency. Calculate Fibonacci numbers: The tail recursive function fibonacci_helper uses optimization to efficiently calculate Fibonacci numbers.

See all articles