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; }