Help Information and Tips
Hints/Tips
Often time when string processing you should consider creating a state machine for your logic and flushing out how the transformations will work. For example, the print_words() function needs to keep track of when words begin and end. Given you pre-processed the input, for example " hello class" would already have been transformed into "hello class...........<to end of buffer>" you can assume the first character is the start of a word. You can then increment your word counter, and set start of word to false. If you encounter a space, you set start of word to true. If you don't encounter a space you print the character. When just getting started sometimes its even helpful to map out an approach before you write code. For example:
int print_words(char *buff, int buff_len, int str_len) where:
- buff is a pointer to the buffer
- buff_len is the total lenght of the buffer
- str_len is the length of total characters in the buffer
remember the buffer is padded with '.'
PRECONDITIONS:
if (str_len > buff_len) > sanity check, return error
if (str_len == 0) buff is empty return 0 no words
RETURNS
The count of the number of words
APPROACH
word_count = 0 to start
char_ctr = 0 lenght of current word
at_start = true this will capture a if we are at the start of a word
loop over each character
if (at_start == true)
increment word_count
set at_start = false (we are processing a new word)
let c = current_char_in_buffer
if (c == ' ') we hit the end of the word
print char_count (length of current word)
set char_ctr = 0 (start count for next word)
set at_start = true (we are starting next word)
else we are just encountering a regular character
print c (current character)
char_ctr++ (add to length of current string)
all characters processed
print char_count (this is for the last word)
return word_count (holds total number of words)Notice how we have one boolean at_start that is used to manage state with respect to finding word boundaries.