C++ 计算数列数字之和 - 代码示例

#include using namespace std;

int main() { int N; cin >> N;

int sum = 0;
for (int i = 1; i <= N; i++) {
    int num = i;
    while (num > 0) {
        sum += num % 10;
        num /= 10;
    }
}

cout << sum << endl;

return 0;

}