20160909 my solution

20160909.c

#include <stdio.h>
#include <sdtlib.h>

#define lastWords(a,b) if(a){printf(b);exit(EXIT_FAILURE);}

typedef struct v_item_t v_item_t;
typedef struct v_set_t v_set_t;
typedef struct v_t v_t;
typedef struct simbolTable_t st_t;

struct v_item_t{
	v_t *this;
	v_item_t *next,*previous;
	int st_index;//?needed?
}

struct v_set_t{
	st_t *taken;
	v_item_t *list;
}

struct v_t{
	char *name;
	v_item_t *edges;
}

struct symbolTable_t{
	int size;
	char **names;
	v_item_t **pointers;
}

v_set_t *loadSet(FILE *input);
v_set_t *selectVerticesFromFile(FILE *input, v_set_t *set);
int verifyIS(v_set_t *set);
v_set_t *maxIS(v_set_t *set);
v_set_t *maxIS_r(v_set_t *set, v_item_t *from);
v_item_t stPointerByName(st_t *st, char *n);
void stRemove(st_t *st, char *n);
void fprintSet(FILE *output, v_set_t *set);
void freeSet(v_set_t *set);
void freeSetNoV(v_set_t *set);
void stInsert(st_t *st, char *n, v_item_t *pointer);

int main(int argc, char **argv){
	FILE *input1, *input2, *output;
	v_set_t *set, *reduced, *max;

	lastWords(argc!=4,"Wrong parameters, expected 3 file names.\n");

	input1=fopen(argv[1],"r");
	lastWords(input1==NULL,"Can NOT open first input file.\n");

	set=loadSet(input1);

	fclose(input1);

	input2=fopen(argv[2],"r");
	lastWords(input2==NULL,"Can NOT open second input file.\n");

	reduced=selectVerticesFromFile(input2,set);

	fclose(input2);

	if(verifyIS(reduced))
		printf("It's an independent set!\n");
	else
		printf("Not an independent set!\n");

	freeSetNoV(reduced);

	max=maxIS(set);

	output=fopen(argv[3],"w");
	lastWords(output==NULL,"Error output file.\n");

	fprintSet(output,max);

	fclose(output);

	freeSet(set);
	freeSet(max);

	return 0;
}

int verifySet(v_set_t *set){
	v_item_t *tmpv,*tmpe;

	for(tmpv=set->list;tmp!=NULL;tmpv=tmpv->next)
		for(tmpe=tmpv->this->edges;tmpe!=NULL;tmpe=tmpe->next)
			if(stPointerByName(set->taken,tmpe->this->name)!=NULL)
				return 0;
	return 1;
}

v_set_t *maxIS_r(v_set_t *set, v_item_t *from){
	v_item_t *tmp;

	if(verifyIS(set))return set;

	for(tmp=from;tmp!=NULL;tmp=tmp->next){
		stRemove(set->taken,tmp->this->name);

		set->list=listRemove(set->list,tmp);

		maxIS(set,tmp->next);

		set->list=listInsertBefore(set->list,tmp->next,tmp);
		stInsert(set->taken,tmp->this->name,tmp);
		maxIS(set,tmp->next);
	}
	return NULL;
}