I am using an Adjacency list to construct a directed graph. I have the vertexs working properly but when it comes to making a vertex have more than one edge I am having trouble. I am also unsure of how to correctly travese through multiple edges for the purpose of printing the adjacency list. What I have at the moment is causing a segmentation fault but I would like to figure out how to correctly build the list first. I will include the main, header file, test data, and the output I am receiving.I can post the other two functions if requested. The section of code that I feel the problem is occurring in is right after I call adjListLocate twice and I am dealing with edges. I am trying to make a new edge and have it point to the old one and then have the vertex point to the new edges but that isn't happening.
main.c
#include "my.h"
int main (int argc, char* argv[])
{
VERTEX *adjList;
adjList = (VERTEX*)calloc(26, sizeof(VERTEX));
//adjList = malloc(sizeof(VERTEX)*26);
FILE* p;
char a;
char b;
int check1 = 0;
int check2 = 0;
int size = 0;
int i;
int aloc = 0;
int bloc = 0;
//Statements
if (argc != 2)
{
fprintf(stderr, "Usage: %s file\n", argv[0]);
return 1;
}
if ((p = fopen(argv[1], "r")) == 0)
{
fprintf(stderr, "Failed to open file %s for reading \n", argv[1]);
return 1;
}
while(fscanf(p," %c %c", &a, &b) == 2)
{
printf("a: %c b: %c\n",a,b);
check1 = adjListSearch(a,size,adjList);
if(check1==1)
{
printf("Adding a = %c\n", a);
adjList[size++].c = a;
}
check2 = adjListSearch(b,size,adjList);
if(check2==1)
{
printf("Adding b = %c\n", b);
adjList[size++].c = b;
}
aloc = adjListLocate(a,size,adjList);
bloc = adjListLocate(b,size,adjList);
EDGE* e = (EDGE*)malloc(sizeof(EDGE));
e->v = &adjList[bloc];
if(*&adjList[aloc].p)
{
EDGE* f = (EDGE*)malloc(sizeof(EDGE));
f->v = &adjList[bloc];
f->q = (*&adjList[aloc]).p;
(*&adjList[aloc]).p = f;
printf("Edge Test: %c %c %c\n", f->v->c, f->q->v->c, f->q->v->c);
}
else
{
(*&adjList[aloc]).p = e;
e->q = NULL;
}
}
//End While
printf("Size: %d\n", size);
for(i=0;i<size;i++)
{
printf(" %c", adjList[i].c);
if(adjList[i].p)
{
VERTEX* z = (VERTEX*)malloc(sizeof(VERTEX));
EDGE* temp = (EDGE*)malloc(sizeof(EDGE));
z = &adjList[i];
//printf("Edge: %c\n", z->p->v->c);
temp = z->p;
while(temp->v->c)
{
printf("test\n");
printf("Edge: %c\n", temp->v->c);
temp = temp->q;
printf("test2\n");
}
}
printf("\n");
}
fclose(p);
return 0;
}
//End main
my.h
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
/* Forward declaration */
struct EDGETAG;
typedef struct
{
char c;
bool isVisited;
struct EDGETAG* p;
} VERTEX;
typedef struct EDGETAG
{
VERTEX* v;
struct EDGETAG* q;
} EDGE;
int main (int argc, char* argv[]);
int adjListSearch (char a, int size, VERTEX* adjList);
int adjListLocate (char a, int size, VERTEX* adjList);
data
A B
C C
E X
C D
C F
C X
sample output
a: A b: B
empty
Adding a = A
not found B
Adding b = B
a: B b: C
found B
not found C
Adding b = C
a: E b: X
not found E
Adding a = E
not found X
Adding b = X
a: C b: D
found C
not found D
Adding b = D
a: C b: F
found C
not found F
Adding b = F
Edge Test: F D D
a: C b: X
found C
found X
Edge Test: X F F
Size: 7
Atest
Edge: B
test2
Segmentation fault
The edge test is what I am worried about here. I would want it to say Edge Test: X F D