题解 | #规律数列求和#
规律数列求和
http://www.nowcoder.com/practice/e05d1c142b3d4898be7183289a00ce5f
```#include <iostream>
#include <cmath>
using namespace std;
int main() {
// write your code here......
long long int sum=0;
int count=1;
for(int i=1;i<=10;i++){
sum+=pow(10,count)-1;
count++;
}
cout<<sum<<endl;
return 0;
}