$1)$ Compile and run the interpreter using a sample program to this language $($Simplified$-$ Infix$-$Expression$),$ which does not allow spaces. Please try the following expression $($interactive keyboard input$)$ and check the result: $2+3*4/2+3+4*2(2)$ Insert a trace code $($a simple cout statement$)$ in each function $($beginning part$)$ and display the sequence of function names executed during the run.$(3)$ Upgrade the code for the following requirements: $1.$ Input is from a text file; $2.$ Input expression can include spaces, e$.$g$.,2+3*4...$ After completing the code, please create a text file and type: $2+3*4/2+3+4*2($be sure to include spaces$)$ and run the interpreter with the input file. If your interpreter does not return the correct result, update your code until well done.$(4)$ Decorate your code with a good documentation, i$.$e$.,$ the global documentation $($at the beginning of the program$)$ and each function head documentation. The global documentation should include the description of the whole program $($what it does, how it is implemented, etc.$),$ input$/$output description, how to compile and run, etc. Each function head doc. should describe what that function does, input$/$output$,$ etc.