DouKaku?

#include <iostream>

void count(int n)
{
    int d = 1;
    int i = 0;
    while(i <= n)
    {
        std::cout << i << std::endl;
        i += d;
        if((i / (d * 10) > 0))
        {
            d *= 10;
        }
    }
}

int main(int, char* [])
{
    count(300);

    return 0;
}