C 面試題目

String copy

char* gstrcpy(char* dstr, char* sstr){

    if (dstr == NULL) return NULL;
    if (sstr == NULL) return NULL;

    char* temp = dstr;
    while(*dstr++ = *sstr++);
    return temp;
}

String cat

char* gstrcat(char* dstr, char* sstr){

    if (dstr == NULL) return NULL;
    if (sstr == NULL) return NULL;

    char* temp = dstr;
    dstr = dstr+sizeof(dstr);
    while(*dstr++ = *sstr++);
    return temp;
}