ListNode *newnode 创建新结点 new ListNode(x, NULL); if(frst==NULL‖i==0){∥插在表前 newnode-> link= first first= current newnode eise ∥/插在表中或末尾 newnode->link= current->link. current=current->link=newnode, return 1ListNode *newnode = //创建新结点 new ListNode(x, NULL); if ( first == NULL || i == 0 ) { //插在表前 newnode->link = first; first = current = newnode; } else { //插在表中或末尾 newnode->link = current->link; current = current->link = newnode; } return 1; }