c - 删除最后一个链接列表

Question

我似乎无法摆脱额外的链表。我知道有很多方法可以做到这一点，但我只想一种简单的方法来释放它，因为它是作为我的循环中的额外内容创建的。这是代码:

    current = first = malloc (sizeof (NODE));
    while( fscanf( fin, "%s", current -> seq) != EOF) {
            for (i = 0; i < 300; i++){
                    if (current->seq[i] == 'a')
                            current->seq[i] = 'A';
                    else if (current->seq[i] == 't')
                            current->seq[i] = 'T';
                    else if(current->seq[i] == 'g')
                            current->seq[i] = 'G';
                    else if(current->seq[i] == 'c')
                            current->seq[i] = 'C';
            }
            if ( (current -> next = malloc ( sizeof(NODE) ) ) == NULL){
                    fprintf(fout, "Out of memory\nCan't add more DNA sequences\n");
                    return EXIT_FAILURE;
            }
            current = current -> next;
    }

Answer 1

将代码的最后一部分替换为

prev= NULL;
current = first =...
...
} //end if
prev = current;
current = current->next;
} //end while

free(current)
if(prev !=NULL)
prev->next = Null;