Simple Calculator

I wrote this to learn C and I learned from my mistakes a lot when the code started to work for only sometimes :^)

• Variables

• Syntax Checking is not perfect at the moment.

Example

5+3
>8
ans+13
>21
xyz=(ans-3)*(PI--+5)
a=5*3
a
>15
ans
>15
E
>2.71...
PI
>3.1415...

With 0.25 percentage of working for a single input, the probability of the example working is

0.25^8
>Segmantation fault (core dumped)