form the vowel string ' vstr ' and consonant string ' cstr ' which contains characters in lexicographical order
for i in range ( SIZE ) : NEW_LINE INDENT ch = chr ( i + 97 ) NEW_LINE for j in range ( 1 , char_freq [ i ] + 1 ) : NEW_LINE INDENT if isVowel ( ch ) : NEW_LINE INDENT vstr += ch NEW_LINE DEDENT else : NEW_LINE INDENT cstr += ch NEW_LINE DEDENT DEDENT DEDENT