Home Java Javagetting Started Three ways to calculate the sum of positive integers within 100 in Java

Three ways to calculate the sum of positive integers within 100 in Java

Oct 22, 2020 pm 06:15 PM
java positive integer

Three ways to calculate the sum of positive integers within 100 in Java

The method is as follows:

(Recommended tutorial: java course)

1. Brutal solution

Use for loop to directly solve the problem one by one, the algorithm complexity is O ( n ) O(n)O(n)

    /**
     * <p>暴力解法</p>
     * @param startInclusive
     * @param endExclusive
     * @return
     */
    public int sumByDirect(int startInclusive, int endExclusive){
        int sum = 0;
        for (int i = startInclusive; i < endExclusive; i++) {
            sum += i;
        }
        return sum;
    }
Copy after login

2. Flow programming

is the same as the brute force solution, but uses declarations A flow programming style with less code and more readability

    /**
     * <p>流式编程</p>
     * @param startInclusive
     * @param endExclusive
     * @return
     */
    public int sumByStream(int startInclusive, int endExclusive){
        return IntStream.range(startInclusive, endExclusive).sum();
    }
Copy after login

3. Using the summation formula

Using the arithmetic sequence summation formula

complex The degree is O ( 1 ) O(1)O(1)

    /**
     * <p>利用求和公式</p>
     * @param startInclusive
     * @param endExclusive
     * @return
     */
    public int sumByFormula(int startInclusive, int endExclusive){
        return ((startInclusive + endExclusive - 1) * (endExclusive - startInclusive) )  >> 1;
    }
Copy after login

Test:

    @Test
    public void Test() {
        System.out.println("sumByDirect=" + sumByDirect(1, 101));
        System.out.println("sumByStream=" + sumByStream(1, 101));
        System.out.println("sumByFormula=" + sumByFormula(1, 101));
    }
Copy after login

Output result:

sumByDirect=5050
sumByStream=5050
sumByFormula=5050
Copy after login

Related recommendations:javaGetting Started

The above is the detailed content of Three ways to calculate the sum of positive integers within 100 in Java. 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)

Perfect Number in Java Perfect Number in Java Aug 30, 2024 pm 04:28 PM

Guide to Perfect Number in Java. Here we discuss the Definition, How to check Perfect number in Java?, examples with code implementation.

Weka in Java Weka in Java Aug 30, 2024 pm 04:28 PM

Guide to Weka in Java. Here we discuss the Introduction, how to use weka java, the type of platform, and advantages with examples.

Smith Number in Java Smith Number in Java Aug 30, 2024 pm 04:28 PM

Guide to Smith Number in Java. Here we discuss the Definition, How to check smith number in Java? example with code implementation.

Java Spring Interview Questions Java Spring Interview Questions Aug 30, 2024 pm 04:29 PM

In this article, we have kept the most asked Java Spring Interview Questions with their detailed answers. So that you can crack the interview.

Break or return from Java 8 stream forEach? Break or return from Java 8 stream forEach? Feb 07, 2025 pm 12:09 PM

Java 8 introduces the Stream API, providing a powerful and expressive way to process data collections. However, a common question when using Stream is: How to break or return from a forEach operation? Traditional loops allow for early interruption or return, but Stream's forEach method does not directly support this method. This article will explain the reasons and explore alternative methods for implementing premature termination in Stream processing systems. Further reading: Java Stream API improvements Understand Stream forEach The forEach method is a terminal operation that performs one operation on each element in the Stream. Its design intention is

TimeStamp to Date in Java TimeStamp to Date in Java Aug 30, 2024 pm 04:28 PM

Guide to TimeStamp to Date in Java. Here we also discuss the introduction and how to convert timestamp to date in java along with examples.

Java Program to Find the Volume of Capsule Java Program to Find the Volume of Capsule Feb 07, 2025 am 11:37 AM

Capsules are three-dimensional geometric figures, composed of a cylinder and a hemisphere at both ends. The volume of the capsule can be calculated by adding the volume of the cylinder and the volume of the hemisphere at both ends. This tutorial will discuss how to calculate the volume of a given capsule in Java using different methods. Capsule volume formula The formula for capsule volume is as follows: Capsule volume = Cylindrical volume Volume Two hemisphere volume in, r: The radius of the hemisphere. h: The height of the cylinder (excluding the hemisphere). Example 1 enter Radius = 5 units Height = 10 units Output Volume = 1570.8 cubic units explain Calculate volume using formula: Volume = π × r2 × h (4

Create the Future: Java Programming for Absolute Beginners Create the Future: Java Programming for Absolute Beginners Oct 13, 2024 pm 01:32 PM

Java is a popular programming language that can be learned by both beginners and experienced developers. This tutorial starts with basic concepts and progresses through advanced topics. After installing the Java Development Kit, you can practice programming by creating a simple "Hello, World!" program. After you understand the code, use the command prompt to compile and run the program, and "Hello, World!" will be output on the console. Learning Java starts your programming journey, and as your mastery deepens, you can create more complex applications.

See all articles