Quick Start: Using functions in the Go language to implement the prime number judgment algorithm

Quick Start: Use functions in Go language to implement prime number determination algorithm

Introduction
Prime numbers refer to numbers that can only be divided by 1 and itself. In computer algorithms, determining whether a number is prime is a frequently used basic operation. This article will introduce how to use functions in the Go language to implement a simple prime number judgment algorithm.

Implementation Idea
To determine whether a number n is a prime number, we can start from 2 and try to divide n by every number j that is less than n. If the result of the division is not an integer, then n is Prime number. The time complexity of this algorithm is O(n), which will be more time-consuming for larger numbers.

Code implementation
The following is a sample code for a prime number judgment algorithm implemented in Go language:

package main

import (

"fmt"
"math"

)

// Determine whether a number is prime
func isPrime(n int) bool {

if n <= 1 {
    return false
}

// 判断n是否能被2到n的平方根之间的任意数整除，如果能则不是素数
sqrt := int(math.Sqrt(float64(n)))
for i := 2; i <= sqrt; i++ {
    if n%i == 0 {
        return false
    }
}

return true

}

func main() {

// 验证一些数是否为素数
numbers := []int{2, 3, 5, 7, 9, 11, 13, 15, 17, 19}
for _, num := range numbers {
    if isPrime(num) {
        fmt.Printf("%d是素数

", num)

    } else {
        fmt.Printf("%d不是素数

", num)

    }
}

}

Run the above code, the output result is as follows:

2 is a prime number
3 is a prime number
5 is a prime number
7 is a prime number
9 is not a prime number
11 is a prime number
13 is a prime number
15 is not a prime number
17 is a prime number
19 is Prime number

Code analysis
isPrime function is used to determine whether a number is prime. First, it is judged that if n is less than or equal to 1, it is definitely not a prime number and returns false directly. Then it loops through every number i from 2 to the square root of n, returning false if n is divisible by i. After the loop ends, if no number is found that can divide n, true is returned.

In the main function, we determine whether some numbers are prime by calling the isPrime function. Put these numbers in a slice, loop through each number in the slice, and output the judgment result.

Conclusion
This article uses the Go language to implement an example of a prime number judgment algorithm to help readers quickly get started with the use of functions in the Go language and learn how to solve practical problems. Prime number judgment is a common problem in algorithms. Mastering such basic algorithms can improve programming abilities.

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