For the purposes of spell checking, a word is a sequence of one or more characters that

Begins and ends with a letter (i.e., a character for which isalpha is true) and
Contains no spaces (i.e., characters for which isspace is true).

In the input text, any two consecutive words are separated by a sequence of non-letter characters containing at least one whitespace character. Although words in the input text may be mixed-case, your program will always convert words to lowercase (using tolower) before comparing them against words in the dictionary. Thus, if your input was STOP! -- don't "dispatch" C.I.A. under-secretary Jones!, the words in that input are stop, don't, dispatch, c.i.a, under-secretary, and jones. Dictionary files are a sequence of unique lowercase words separated by whitespace. Words may occur in dictionary files in any order, without duplication.

Output Format

Each line in the correction output should consist of the incorrect word followed by a colon (:) and zero or more corrections separated by spaces. There should be exactly one space after the colon (unless there are no corrections), and there should be no whitespace at the end of each line. The following example shows valid output:

``` unix$ ./myspell smalldict.words < error-filled-file.txt xyzzy: foo: for wird: bird gird ward word wild wind wire wiry ```

If a word is misspelled multiple times in the input file, it should only be printed once. If every word in the input is found in the dictionary, myspell should produce no output on cout, not even an empty line.

Debugging Command-Line Option

Your myspell program must also support a debugging option, whereby the command ./myspell -d ispell.words reads the dictionary ispell.words and performs spell checking as usual, but also prints information about the data structure used to represent the dictionary. The code to process the arguments is provided for you, in myspell.cpp. The debugging information should be printed immediately after the dictionary has been read, before spell checking begins, and sent to cerr (not cout). The exact debugging statistics you calculate will vary depending on the kind of tree you choose to implement.