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POWord occurrences and line numbers
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copied!<p>I'm making a program that generates a text file that contains the occurrences of words and the line number of each occurrence of another text file. I'm using an AVL tree struct that contains the word and a linked list struct that contains one node for each line number. Here are the struct definitions:</p> <pre><code>struct llnode { struct llnode *next; int num; }; struct node { char *word; struct llnode *head; struct node *left; struct node *right; int height; }; </code></pre> <p>I get a segmentation fault when I try to print to the text file using the below functions.</p> <pre><code>void listprint(struct llnode *p) { if(p->next == NULL) { printf("%d", p->num); } else { printf("%d, ", p->num); listprint(p->next); } } void treeprint(struct node *p) { if(p != NULL) { treeprint(p->left); printf("%s: ", p->word); listprint(p->head); treeprint(p->right); } } </code></pre> <p>Specifically the problem is this line</p> <pre><code>if(p->next == null) { </code></pre> <p>gdb gives me</p> <pre><code>Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000 </code></pre> <p>Thanks for your help.</p> <p>Edit:</p> <pre><code>void listinsert(struct llnode *p) { struct llnode *prev = p; while(p != NULL) { prev = p; p = p->next; } p = lalloc(); p->num = line; p->next = NULL; prev->next = p; struct node *addtree(struct node *p, char *w) { int cond; if(p == NULL) { p = talloc(); p->head = NULL; p->word = mystrdup(w); p->head = listinsert(p->head); p->left = p->right = NULL; } else if((cond = strcmp(w, p->word)) == 0) { listinsert(p->head); } else if(cond < 0) { p->left = addtree(p->left, w); if(height(p->left)-height(p->right) == 2) { if(strcmp(w, p->left->word) < 0) { p = singleleft(p); } else { p = doubleleft(p); } } } else { p->right = addtree(p->right, w); if(height(p->right)-height(p->left) == 2) { if(strcmp(w, p->right->word) > 0) { p = singleright(p); } else { p = singleleft(p); } } } return p; int getword(char *word, int lim) { int c; char *w = word; while(isspace(c = getch())); if(c == '\n') { line++; } if(c != EOF) { *w++ = c; } if(!isalpha(c)) { *w = '\0'; return c; } for( ; --lim > 0; w++) { if(!isalnum(*w = getch())) { ungetch(*w); break; } } *w = '\0'; return word[0]; </code></pre>

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