题目：求s=a+aa+aaa+aaaa+aa...a的值，其中a是一个数字。例如2+22+222+2222+22222(此时共有5个数相加)， 几个数相加由输入控制。

Posted 2022-02-25 squirrel-xie

public class MultiSum 
    public static void main(String[] args) 
        Scanner scan = new Scanner(System.in);
        System.out.println("请输入一个一位数");
        int num = scan.nextInt();
        System.out.println("请输入该数最多时的个数");
        int times = scan.nextInt();
        System.out.println("您输入的结果为：");
        int result =sum(num,times);
        System.out.print(result);
        scan.close();
    
    
    public static int sum(int num,int times) 
        int result =0;
        String str = "";
        for(int i=0;i<times;i++) 
            //搞个字符串，依次循环，要几个数就乘以几个1
            str += "1";
            int a =Integer.valueOf(str);
            System.out.print(num*a);
            if(i<times-1) 
                System.out.print("+");
            else 
                System.out.print("=");
            
            result += num*a;
        
        return result;