#include <iostream>
using namespace std;
int main()
{
    float i = 1;
    do
    {
        cout<<i<<"\n";
        i = i + 0.1;
    } while (i <= 2.1);
    return 0;
}

kodingwindow@kw:~$ g++ kw.cpp
kodingwindow@kw:~$ ./a.out
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
kodingwindow@kw:~$