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

You can do this in C like this:

unsigned int coltonum(char * string)
{
   unsigned result = 0;
   char ch;

   while(ch = *string++)
      result = result * 26 + ch - 'A' + 1;

  return result;
}

No error checking, only works for upper case strings, string must be null terminated.