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#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
const char* next_word(void){
static char buf[1024];
int len=0;
char c=getchar();
while(isspace(c))c=getchar();
if(feof(stdin))return NULL;
if(!isalnum(c)){
buf[0]=c;
buf[1]='\0';
return buf;
}
while(isalnum(c)&&!feof(stdin)){
buf[len++]=c;
c=getchar();
}
if(!feof(stdin))ungetc(c,stdin);
buf[len]='\0';
return buf;
}
struct rule {
int state;
int direction; // right = 1, left = -1
bool value;
};
struct rules {
struct rule table[8][2];
int start;
int stopcount;
};
#define EQ(s1_,s2_) (strcmp((s1_),(s2_))==0)
#define READ(dest_) assert((dest_)=next_word())
#define READ_EOF(dest_) ((dest_)=next_word())
#define READSTATE(dest_) ((dest_)=next_word()[0]-'A')
#define READINT(dest_) ((dest_)=strtol(next_word(),NULL,10))
#define EXPECT(s_) assert(EQ(next_word(),(s_)))
static struct rules parse(void){
struct rules R;
int curstate=0,curval=0;
const char *word;
while(true){
READ_EOF(word);
if(!word)break;
if(EQ(word,"Begin")){
EXPECT("in"); EXPECT("state");
READSTATE(R.start);
EXPECT(".");
} else if(EQ(word,"Perform")){
EXPECT("a"); EXPECT("diagnostic"); EXPECT("checksum"); EXPECT("after");
READINT(R.stopcount);
EXPECT("steps"); EXPECT(".");
} else if(EQ(word,"In")){
EXPECT("state");
READSTATE(curstate);
EXPECT(":");
} else if(EQ(word,"If")){
EXPECT("the"); EXPECT("current"); EXPECT("value"); EXPECT("is");
READINT(curval);
EXPECT(":");
} else if(EQ(word,"-")){
READ(word);
if(EQ(word,"Write")){
EXPECT("the"); EXPECT("value");
READINT(R.table[curstate][curval].value);
EXPECT(".");
} else if(EQ(word,"Move")){
EXPECT("one"); EXPECT("slot"); EXPECT("to"); EXPECT("the");
READ(word);
if(EQ(word,"right"))R.table[curstate][curval].direction=1;
else if(EQ(word,"left"))R.table[curstate][curval].direction=-1;
else assert(false);
EXPECT(".");
} else if(EQ(word,"Continue")){
EXPECT("with"); EXPECT("state");
READSTATE(R.table[curstate][curval].state);
EXPECT(".");
} else {
assert(false);
}
} else {
assert(false);
}
}
return R;
}
#undef EQ
#undef EXPECT
static void printrules(const struct rules R){
printf("start=%c\nstopcount=%d\n",R.start+'A',R.stopcount);
for(int i=0;i<8;i++){
printf("%c: %d,%c,%c %d,%c,%c\n",
'A'+i,
R.table[i][0].value,"<>"[R.table[i][0].direction],R.table[i][0].state+'A',
R.table[i][1].value,"<>"[R.table[i][1].direction],R.table[i][1].state+'A');
}
}
int main(void){
freopen("25.in","r",stdin);
struct rules R=parse();
// printrules(R);
assert(sizeof(bool)==1);
int tapesize=4096;
bool *tape=calloc(tapesize,1);
int state=R.start,ptr=tapesize/2;
for(int iter=0;iter<R.stopcount;iter++){
if(ptr==-1){
bool *newtape=calloc(2*tapesize,1);
memcpy(newtape+tapesize,tape,tapesize);
ptr+=tapesize;
free(tape);
tape=newtape;
tapesize*=2;
} else if(ptr==tapesize){
bool *newtape=calloc(2*tapesize,1);
memcpy(newtape,tape,tapesize);
free(tape);
tape=newtape;
tapesize*=2;
}
struct rule *rule=&R.table[state][tape[ptr]];
tape[ptr]=rule->value;
ptr+=rule->direction;
state=rule->state;
}
int total=0;
for(int i=0;i<tapesize;i++)total+=tape[i];
printf("%d\n",total);
free(tape);
}
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