题解 | #规律数列求和#
规律数列求和
https://www.nowcoder.com/practice/e05d1c142b3d4898be7183289a00ce5f
#include <iostream>
using namespace std;
int main() {
int n = 10;
long long sum = 0;
long long term = 9;
for (int i = 1; i <= n; ++i)
{
sum += term;
term = term * 10 + 9;
}
cout << "" << sum << endl;
return 0;
}
