背景
没事写了个简单的统计单词个数的程序，特记录下。
代码
struct word_node{
char word[MAX_WORD_SIZE];
int counter;
struct word_node
*next;
}
*word_list = NULL;
typedef struct word_node word_list_t;
int get_file_size(char
*file_name)
{
struct
stat s;
stat(file_name, &
s);
return s.st_size;
}
int is_existed(char
*word)
{
word_list_t
*ptr = NULL;
/* compare the word with already words in list */
for (ptr=word_list; ptr; ptr=ptr->
next){
if (strcmp(word, ptr->word) ==
0){
ptr->counter++;
return 1;
}
}
return 0;
}
int create_new_word(char
*word)
{
word_list_t
*new_node = NULL;
word_list_t
*ptr = NULL;
word_list_t
*pre = NULL;
new_node = (word_list_t
*)malloc(sizeof(word_list_t));
if (new_node == NULL){
printf(
"malloc error");
return -
1;
}
strcpy(new_node->word, word);
new_node->counter =
1;
if (word_list == NULL){
word_list = new_node;
}
else{
for (ptr=word_list; ptr; ptr=ptr->
next){
pre = ptr;
}
pre->
next = new_node;
}
return 0;
}
int quick_sort(word_list_t
*head, word_list_t
*tail)
{
int counter;
word_list_t
*mid = NULL;
word_list_t
*p = NULL;
word_list_t
*q = NULL;
word_list_t
*t = NULL;
if ((head->
next == tail) || (head->
next->
next == tail))
return 0;
mid = head->
next;
p = head;
q = mid;
counter = mid->counter;
t = mid->
next;
while (t != tail){
if (t->counter < counter){
p = p->
next = t;
}
else{
q =
q->
next = t;
}
t = t->
next;
}
p->
next = mid;
q->
next = tail;
quick_sort(head, mid);
quick_sort(mid, tail);
return 0;
}
int show_words()
{
word_list_t
*ptr = NULL;
printf(
"the words list:\n");
printf(
"word counters\n");
printf(
"----------------------------------------\n");
for (ptr=word_list; ptr; ptr=ptr->
next){
printf(
"%-32s M\n", ptr->word, ptr->counter);
}
return 0;
}
int main(char argc, char
**argv)
{
int ret = -
1;
FILE
*fp = NULL;
char
*file_name = NULL;
char line[MAX_LINE_SIZE];
char
*delim =
".,! ";
char
*token = NULL;
char
*saveptr = NULL;
char
*str = NULL;
/* check args */
if (argc !=
2){
printf(
"Usage: %s filename\n", argv[
0]);
return -
1;
}
/* check size of file
*/
file_name = argv[
1];
if (get_file_size(file_name) > MAX_FILE_SIZE){
printf(
"the size of file too large.\n");
return -
1;
}
/*
open file
*/
fp = fopen(file_name,
"r");
if (fp == NULL){
printf(
"open file error.\n");
return -
1;
}
/*
read words line by line
*/
while (fgets(line, MAX_LINE_SIZE, fp) != NULL){
/* delete the '\n' of line */
line[strlen(line)-
1] =
'\0';
str = line;
/* parse words in this line */
while (
1){
token = strtok_r(str, delim, &saveptr);
if (token == NULL){
break;
}
str = NULL;
/* check the length of word */
if (strlen(token) > MAX_WORD_SIZE){
printf(
"the word[%s] is too long.\n", token);
return -
1;
}
/*
if existed, update counters of the word
*/
if (is_existed(token)){
;
}
/*
not, create new node to store the word
*/
else{
create_new_word(token);
}
}
}
/*
sort by ascending order
*/
quick_sort(word_list, NULL);
/* show words infor */
show_words();
return 0;
}
