三个初级的Java算法函数

1.九九乘法表

public class nineplusnine {
    
public static void main(String args[]) {
    for(int i = 1;i<=9;i++){
        for(int j =1;j<=9;j++) {
            System.out.print(i*j+" ");
            
        }
        System.out.println(" ");
    }
}
}

2.寻找1000以内的素数

public class FindPrimeNumber {
public static  void main (String args[]) {
    
 for(int i = 2;i<1000;i++) {
     boolean c = true;
     for(int j=2;j<i;j++) {
         if(i%j == 0) {
             c = false;
             break;
            
         }      
     }
     if(c) 
     {
         System.out.print(i+" ");
     }
 }    
}
}

3.阶乘

import java.util.Scanner;

public class factorial {
public static void main(String args[]){
        int r= 1;
    System.out.println("Please input the number");
    Scanner scan = new Scanner(System.in);
    int s =scan.nextInt();
    for (int i = 1;i<=s;i++) {
        
            r= r*i;
    }
    System.out.println(r);
    return;
}
}