c语言用链表实现，统计一个英文文本文件中每个单词的出现次数（词频统计)，结果按单词词典序输出到屏幕

#include
#include
int main(void)
{
int a = 0, b = 0, c = 0;
char buf[128];
FILE *fp;
/* 打开文件，文件名必须大写 */
fp= fopen("DATA5610.TXT", "r");
if (!fp) {
printf("No 'DATA5610.TXT' found.\n");
return -1;
}
/* 逐次读取单词，空格或回车分割 */
while (fscanf(fp, "%s", buf) > 0) {
/* 如读取到的单词是 if，则a自增 1 */
if (strcmp(buf, "if") == 0)
a++;
else if (strcmp(buf, "while") == 0)
b++;
else if (strcmp(buf, "for") == 0)
c++;
}
printf("if: %d, while: %d, for: %d\n", a, b, c);
fclose(fp);
return 0;
}