10.4 输入一行字符，用函数编程统计其中有多少个单词。假设单词之间以空格分开

# include <stdio.h>
# include <string.h>
void  panduan(char *p, int *n);
void main()
{
int a, *m;
m = &a;
FILE *fp = fopen("words.dat", "w+");
char str[100];
printf("请您输入字符串：\n");
gets(str);
fprintf(fp,"字符串：\n%s\n", str);
panduan(str, m);
printf("%d\n",a);
puts(str);
fprintf(fp,"单词个数：\n%d\n", a);
fclose (fp);
}
void panduan(char *p, int *n)
{
*n = 1;
for (; *p!='\0'; p++)
if (*p == ' ')
*n += 1;
}