题解 | #规律数列求和#
规律数列求和
https://www.nowcoder.com/practice/e05d1c142b3d4898be7183289a00ce5f
#include <iostream>
#include <cmath>
using namespace std;
int main() {
// write your code here......
//+= 9*= (10*i)
long long sum;
for(int i = 0; i <= 10; i++)
{
sum += pow(10,i)-1;
}
cout<<sum<<endl;
return 0;
}
pow(10,i)-1 就是9,99,999...了
