Programming Riddle: How might you translate an Excel column name to a number?

Question

I was recently asked in a job interview to resolve a programming puzzle that I thought it would be interesting to share. It\'s about translating Excel column letters to actu

Answer 1

another [more cryptic] erlang example:

col2int(String) -> col2int(0,String).
col2int(X,[A|L]) when A >= 65, A =< 90 ->
col2int(26 * X + A - 65 + 1, L);
col2int(X,[]) -> X.

and inverse function:

int2col(Y) when Y > 0 -> int2col(Y,[]).
int2col(0,L) -> L;
int2col(Y,L) when Y rem 26 == 0 -> 
   int2col(Y div 26 - 1,[(26+65-1)|L]);
int2col(Y,L) ->
   P = Y rem 26,
   int2col((Y - P) div 26,[P + 65-1|L]).