char* Strcpy(char* target, const char* source) {
    char* t = target;
    while ( *t++ = *source++ );
    return target;
}

char* Strcat(char* target, const char* source) {
    char* t = target-1;
    while ( *++t );
    while ( *t++ = *source++ );
    return target;
}

char* Strncat(char* target, const char* source, int n) {
    char* t = target-1;
    while ( *++t );
    while ( (*t++ = *source++) && n--);
    *(t-1) = '\0';
    return target;
}

int Strlen(const char* source) {
    const char* s = source;
    while ( *s++ );
    return s-source-1;
}

char* Strchr(const char* target, int c) {
    while ( *target && *target++ != c );
    return (char*)(*--target ? target : 0);
}