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 
# include 
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;
}