使用递归方法算阶乘、累加、十进制转二进制

public class C8 {

    public static void main(String[] args) {
     

System.out.println(factorial(10));
        
    }
    
    public static int factorial(int n){
        if(n==1)
            return 1;
        else return n*factorial(n-1);
    }    
    
}

public class C8 {

    public static void main(String[] args) {
     

System.out.println(sum(10));
        
    }
    
    public static int sum(int n){
        if(n==1)
            return 1;
        else return n+sum(n-1);
    }    
    
}

public class C8 {

    public static void main(String[] args) {
     

DecimalToBinary(10);
        
    }
    
    public static void DecimalToBinary(int n){
          if(n>0){
            DecimalToBinary(n/2);
               System.out.print(n%2);
          }
    }    
    
}