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copied!<p>Maybe you don't need twice pointers in each structure? You have arrays for chapters, for paragraphs - no need to use twice pointers.</p> <p>Provided code is more likely to use arrays, not lists. So if you are trying to use lists - I mentioned them in the end of answer. Otherwise, it is simpler to fix it to use arrays and here is the first problem:</p> <pre><code>if (++(books->numChapters) > 0) { /* here books are reallocated */ books = realloc(books, sizeof(struct chapter*)*books->numChapters); /* but here chapters which had not been reallocated are acessed */ books->chapters[books->numChapters - 1] = nextChapter; } </code></pre> <p>If you have a new chapter then why do you need to realloc books? Just realloc books->chapters:</p> <pre><code>if (++(books->numChapters) > 0) { books->chapters = realloc(books->chapters, sizeof(struct chapter*)*books->numChapters); books->chapters[books->numChapters - 1] = nextChapter; } </code></pre> <p>And in the end the same issue:</p> <pre><code>/* books are reallocated, size is bad - reallocated to size of numChapters * (pointer size) */ books = realloc(books, sizeof(struct chapter*)*books->numChapters); /* perhaps access to non-allocated memory here */ books->chapters[books->numChapters] = (void*)0; </code></pre> <p>Should be:</p> <pre><code>books->chapters = realloc(books->chapters, sizeof(struct chapter)*books->numChapters); // books->chapters[books->numChapters] = (void*)0; </code></pre> <p>Assigning NULL to the last element is not needed, because chapters has size of numChapters and accessing element numChapters cause access to non-allocaed memory, crash.</p> <p>All the code above uses a conception of arrays, not linked lists.</p> <p>To switch it to linked list it is necessary to use structures like the following:</p> <pre><code>struct paragraph { struct paragraph *next; // <<-- this field is used to build // linked list of paragraphs char* lines; int numLines; }; struct chapter { struct chapter *next; // <<-- this field is used to build // linked list of chapters struct paragraph* paragraphs; int numParagraphs; }; struct book { struct chapter* chapters; int numChapters; }; </code></pre> <p>Sure, appropriate allocations and assignment of "next" pointers are required.</p>

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