Java algorithm to find prime numbers

Question description

Given the interval [L, R], please count the number of prime numbers in the interval.

Input
Input description:
　　Two numbers L and R.
Input example:
2 11

output

Output description:
　　One line, the number of prime numbers in the interval.
Output sample:
5

HINT: Time limit: 1.0s Memory limit: 256.0MB
　　2 <= L <= R <= 2147483647 R-L <= 1000000

Problem-solving ideas

Just judge the number of prime numbers in the interval directly, and be careful to remove even numbers.

code

import java.util.Scanner;

public class Main {
    
    

    public static void main(String[] args) {
    
    
        Scanner scanner=new Scanner(System.in);
        int m=scanner.nextInt();    //输入左区间
        int n=scanner.nextInt();    //输入右区间
        int b = 0;          //判断是否为素数的条件
        int a = 0;          //记录素数的个数
        for (int i=m;i<=n;i++){
    
     //循环区间内的数
            if(i!=2&&i%2==0){
    
        //判断是否为偶数且不为2  &&：和， ||：或
                continue;       //跳过本次循环
            }
            for (int j=3;j<i;j+=2){
    
             //循环判断是否为素数
                if (i%j==0){
    
    
                    b++;
                    break;                  //如果不是素数结束循环
                }
            }
            if (b==0){
    
              //素数个数加1
                a++;
            }
            b=0;            //重置判断条件
        }
        System.out.println(a);      //输出素数个数
    }
}