//刪除源字串中的指定子串，使用strstr函式進行查詢
char * deleteSubString(char * srcString, const char * subString)
{
    if (NULL==srcString||NULL==subString) {
        printf("Pointer is NULL\n");
        exit(EXIT_FAILURE);
    }
    //指向第一個subString
    char *p=strstr(srcString, subString);
    if (NULL==p) {
        printf("subString is not exist\n");
        exit(EXIT_FAILURE);
    }
    
    long len=strlen(subString);
    while (p) {
        while (1) {
            //刪除subString
            *p=*(p+len);
            if (*p=='\0') {
                break;
            }
            p++;
        }
        p=strstr(srcString, subString);
    }
    
    return srcString;
}