//计算 9+99+…+9999999999(12个9)
//10^i-1
public class Test2 {
public static void main(String[] args) {
long sum = 0;
for (int i = 1; i <= 12; i++) {
double s = (Math.pow(10, i) - 1); // 此函数用来计算次方函数的值
sum += s;
System.out.println(sum);
}
}
}