题解 | #数列求和#
数列求和
https://www.nowcoder.com/practice/6893484c04c24bfca1f606b1823a468d
public class Main {
public static void main(String[] args) {
//write your code here........
String num = "9";
long sum=9;
for(int i =1;i<10;i++){
num = num+"9";
sum= sum + Long.parseLong(num);
}
System.out.print(sum);
}
}
