fibo.bf

fibo.bf

Program to find the nth term of fibonacci sequence where n is input between 2 and 9 (inclusive)
,                                   input (number between 2 and 9)         

>>++++++[-<++++++++>]<[-<->]<       subtract 48 from the 1st cell (48 is the ASCII value of zero
                                    we subtract inorder to convert from ASCII to integer)

--                                  subtract 2 from the 1st cell since first 2 terms of the 
                                    fibonacci series is 1 and 1

>+>+                                initialize the 2nd and the 3rd cells to 1 (the first 2 terms
                                    of the fibonacci series)

<<                                  goto 1st cell

[                                   loop:

    >[->>+<<]                       copy the 2nd cell to the the 4th cell

    >                               goto 3rd cell 

    [->+>+<<]                       add the value in the 3rd cell to the 4th cell and also
                                    copy the value of the 3rd cell the the 5th cell

    >>                              goto 5th cell

    [-<<<+>>>]                      copy the value of the 5th cell to the 2nd cell

    <                               goto 4th cell

    [-<+>]                          copy the value of 4th cell to the 3rd cell

    <<<                             goto 1st cell

    -                               subtract the value in the 1st cell by 1 and goto next 
                                    iteration of the loop

]                                   end of the loop

>>                                  goto the 3rd cell the 3rd cell contains the answer