Скачать или смотреть 0032 Longest Common Prefix in

The longest method is designed to find the longest common prefix among an array of strings. It starts by checking if the input array strs is empty. If it is, the method immediately returns an empty string, as there are no strings to find a common prefix.

Next, the method uses Java Streams to find the shortest string in the array. This is done because the longest common prefix cannot be longer than the shortest string. The min method of the stream is used, which takes a comparator that compares the lengths of the strings. If no minimum string is found (which is unlikely because we already checked for an empty array), it defaults to an empty string.

After determining the shortest string, the method enters a loop that iterates over each string in the array. For each string, it checks whether the current shortest string (minStr) is a prefix of the string. If not, it reduces the minStr by removing the last character, and then checks again. This process continues until minStr is a prefix of the string or until minStr becomes empty. If minStr becomes empty during this process, it returns an empty string as there is no common prefix.

Finally, after all the strings have been processed, the method returns minStr, which now represents the longest common prefix of the input array.

Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is intended to let application developers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture.

Key Features of Java:
Platform Independence:
Java achieves platform independence at both the source and binary levels. The Java compiler converts the source code into bytecode, which the JVM interprets and executes. This bytecode can be executed on any platform that has a compatible JVM, making Java applications highly portable.

Object-Oriented:
Java is fundamentally object-oriented, meaning it uses objects and classes as the core building blocks of programs. This approach helps to modularize programs, making them easier to understand, maintain, and extend. Key principles of object-oriented programming (OOP) such as inheritance, encapsulation, polymorphism, and abstraction are integral to Java.

Automatic Memory Management:
Java provides automatic memory management through its garbage collection mechanism. This feature helps in reclaiming memory that is no longer in use, thus preventing memory leaks and improving the efficiency of the application.

Robust and Secure:
Java emphasizes early checking for possible errors, as well as runtime checking, to provide a robust programming environment. Its security features, including the absence of explicit pointers and the provision of a security manager, make it a suitable choice for writing secure and stable applications.

Multithreading Support:
Java has built-in support for multithreading, allowing multiple threads of execution to run concurrently. This is particularly useful for developing applications that require parallel processing, such as web servers and graphical user interfaces.

Rich Standard Library:
Java comes with a comprehensive standard library that provides a wide range of classes and methods for various tasks, including data structures, networking, file I/O, graphical user interface (GUI) development, and more. This extensive library helps developers to implement complex functionalities without needing to write code from scratch.

Java Syntax and Structure:
Java syntax is similar to C and C++, which makes it relatively easy for programmers familiar with these languages to learn. However, Java eliminates certain complex and error-prone features of C/C++, such as pointer arithmetic and multiple inheritance, thereby simplifying the programming model.

A basic structure of a Java program includes:

Classes and Objects: Java programs are made up of classes and objects. A class is a blueprint for creating objects, which are instances of classes.
Methods: Methods define the behavior of objects. They contain a sequence of statements that perform a specific task.
Fields: Fields (or variables) store the state of an object.