Ich studiere Turing-Maschinen für meinen Kurs in formaler Sprachtheorie, der Professor empfahl einen Durchlauf mit folgendem Algorithmus um die Logik hinter einem "TM" im Detail zu sehen, aber es funktioniert nicht, wenn ich versuche zu kompilieren, bekomme ich folgenden Fehler.
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c||In function `Tape* insert_tape(Tape*, Direction, char)':|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|44|error: invalid conversion from `void*' to `Tape*'|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c||In function `Tape* create_tape(char*)':|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|68|error: invalid conversion from `void*' to `Tape*'|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c||In function `Transition* get_transition(char*)':|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|80|error: invalid conversion from `void*' to `Transition*'|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c||In function `List* insert_list(List*, char*)':|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|93|error: invalid conversion from `void*' to `List*'|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c||In function `List* insert_list_transition(List*, Transition*)':|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|105|error: invalid conversion from `void*' to `List*'|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c||In function `TM* createTM(char*)':|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|166|error: invalid conversion from `void*' to `TM*'|
C:\Documents and Settings\Melkhiah.EQUIPO01\Mis documentos\Downloads\Tarea3 Discretas\TM.c|167|error: invalid conversion from `void*' to `List*'|
||=== Build finished: 7 errors, 0 warnings ===|Hier ist der Code:
/* This C file implements a Non-determinitic Pushdown Automata
* author: Kevin Zhou
* Computer Science and Electronics
* University of Bristol
* Date: 21st April 2010
*/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct tapes {
struct tapes *left;
struct tapes *right;
char content;
} Tape;
typedef enum { LEFT,RIGHT } Direction;
typedef struct transition {
char current_state;
char tape_symbol;
char new_state;
char new_tape_symbol;
Direction dir;
} Transition;
typedef struct list {
Transition *content;
struct list *next;
} List;
typedef struct tm {
char *input_alpha;
char *input;
char *tape_alpha;
char start;
char accept;
char reject;
List *transition;
} TM;
Tape *insert_tape(Tape *t, Direction dir, char c) {
Tape *head = t;
Tape *new1 = calloc(1,sizeof(Tape));;
new1 -> content = c;
if(dir == LEFT) {
while(t->left != NULL) {
t = t->left;
}
new1->right = t;
new1->left = NULL;
t->left = new1;
return new1;
}
if(dir == RIGHT) {
while(t->right != NULL) {
t = t->right;
}
new1->left = t;
new1->right = NULL;
t->right = new1;
}
return head;
}
Tape *create_tape(char *input) {
int i=1;
Tape *t = calloc(1,sizeof(Tape));
t->content = input[0];
while(1) {
if(input[i] == '\0') break;
t = insert_tape(t,RIGHT,input[i]);
i++;
}
return t;
}
/* turn the input string into Transition fields */
Transition *get_transition(char *s) {
Transition *t = calloc(1,sizeof(Transition));
Direction dir;
t->current_state = s[0];
t->tape_symbol = s[1];
t->new_state = s[2];
t->new_tape_symbol = s[3];
dir = (s[4]=='R')? RIGHT:LEFT;
t->dir = dir;
return t;
}
/* turn the string into transitions and add into list */
List *insert_list( List *l, char *elem ) {
List *t = calloc(1,sizeof(List));
List *head = l;
while(l->next!=NULL)
l = l->next;
t->content = get_transition(elem);
t->next = NULL;
l->next = t;
return head;
}
/* insert a transition into a list */
List *insert_list_transition( List *l, Transition *tr) {
List *t = calloc(1,sizeof(List));
List *head = l;
while(l->next!=NULL)
l = l->next;
t->content = tr;
t->next = NULL;
l->next = t;
return head;
}
void print_tape( Tape *t,char blank) {
char c;
while(1) {
if(t->content != blank) break;
t= t->right;
}
while(1) {
if(t==NULL) break;
c = t->content;
if(t->content != blank)
putchar(c);
t= t->right;
}
putchar('\n');
}
void print_transition (Transition *t) {
char s1[] = "Left";
char s2[] = "Right";
if(t==NULL) {
printf("NULL Transfer");
return;
}
printf("current:%c tape:%c new state:%c new tape:%c direction %s\n",t->current_state,t->tape_symbol,t->new_state,t->new_tape_symbol,(t->dir == LEFT)?s1:s2);
}
/*test if the char c is in the string s */
int contains ( char c, char *s ) {
int i=0;
while(1) {
if(c== s[i]) return 1;
if(s[i] == '\0') return 0;
i++;
}
}
/* test if the input is a valid input */
int is_valid_input( char *input_alpha, char *input ) {
int i=0;
char c;
while(1) {
c = input[i];
if(c == '\0') break;
if(!contains(c,input_alpha)) return 0;
i++;
}
return 1;
}
TM *createTM (char *input) {
TM *m = calloc(1,sizeof(TM));
List *tr = calloc(1,sizeof(List));
char *buffer;
/*read input alphabet of PDA*/
buffer = strtok(input,":");
if(buffer == NULL) {
printf("Error in reading input alphabet!\n");
exit(1);
}
m->input_alpha = buffer;
/*read tape alphabet*/
buffer = strtok(NULL,":");
if(buffer == NULL) {
printf("Error in reading tape alphabet!\n");
exit(1);
}
m->tape_alpha = buffer;
/*read input sequence*/
buffer = strtok(NULL,":");
if(buffer == NULL) {
printf("Error in reading input sequence!\n");
exit(1);
}
if(!is_valid_input(m->input_alpha,buffer)) {
printf("Error! Input contains some invalid characters that don't match the input alphabet!\n");
exit(1);
}
m->input = buffer;
buffer = strtok(NULL,":");
m->start = buffer[0];
buffer = strtok(NULL,":");
m->accept = buffer[0];
buffer = strtok(NULL,":");
m->reject = buffer[0];
/*read tape transition*/
while(1) {
buffer = strtok(NULL,":");
if(buffer == NULL) break;
tr = insert_list(tr,buffer);
}
m->transition = tr->next;
return m;
}
Transition *find_transition(List * list,char state, char tape_symbol) {
Transition *t;
while(1) {
if(list==NULL) return NULL;
t = list -> content;
if(t->current_state == state && t->tape_symbol == tape_symbol)
return t;
list = list->next;
}
}
Tape *move(Tape *t,Direction dir, char blank) {
if(dir == LEFT) {
if(t->left==NULL) {
t = insert_tape(t,LEFT,blank);
}
return t->left;
}
if(dir == RIGHT) {
if(t->right==NULL) {
t = insert_tape(t,RIGHT,blank);
}
return t->right;
}
return NULL;
}
void simulate( TM *m ) {
/* first symbol in input symbol used to represent the blank symbol */
const char blank = m->tape_alpha[0];
char current_state = m->start;
Tape *tape = create_tape(m->input);
Tape *curent_tape = tape;
char current_tape_symbol;
Transition *current_transition;
while(1) {
if(current_state == m->accept) {
printf("Accept\n");
print_tape(tape,blank);
break;
}
if(current_state == m->reject) {
printf("Reject\n");
print_tape(tape,blank);
break;
}
current_tape_symbol = (current_tape==NULL||current_tape ->content == '\0')?blank:current_tape->content;
current_transition = find_transition(m->transition,current_state,current_tape_symbol);
current_state = current_transition -> new_state;
current_tape -> content = current_transition -> new_tape_symbol;
current_tape = move( current_tape, current_transition ->dir, blank);
}
}
int main(void) {
char s[300];
TM *p;
scanf("%s",s);
p = createTM(s);
simulate(p);
return 0;
}Warum funktioniert dieses Programm nicht?
