数据结构——链表学习笔记

由于跨专业找的工作，很多科班的课程只有到现在才来补学，比如很重要的《数据结构》，原来仅仅是使用，知其然而不知其所以然，现在决定花两周时间把课程自学完，关于每张学习的笔记就博客出来，留待自己将来复习。

下面是整数链表的练习程序：

 

public class IntNode { public static void main(String[] args) { IntNode shortList; IntNode copy; shortList = new IntNode(10,null); shortList.addNodeAfter(20); shortList.addNodeAfter(25); shortList.addNodeAfter(30); shortList.addNodeAfter(38); shortList.addNodeAfter(42); shortList.addNodeAfter(55); // IntNode.listCopy()测试 copy = IntNode.listCopy(shortList); System.out.println(IntNode.listLength(copy)); System.out.println(IntNode.listLength(shortList)); // IntNode.listCopyWithTail测试 IntNode[] copyWithTail = IntNode.listCopyWithTail(shortList); System.out.println(copyWithTail[0].getData()); System.out.println(copyWithTail[1].getData()); // IntNode.listData(IntNode head)测试 for (int i = 0 ; i < IntNode.listLength(copy) ; i++ ) { System.out.print(i + 1 + ": " + IntNode.listData(shortList)[i] + "; "); } // IntNode.listPart(IntNode start,IntNode end)测试 System.out.println("--------------------------"); try { IntNode[] listPartCopy = IntNode.listPart(shortList,new IntNode(42,null),new IntNode(25,null)); System.out.println(listPartCopy[0].getData()); System.out.println(listPartCopy[1].getData()); } catch (IllegalArgumentException e) { e.printStackTrace(); } // IntNode.listPostion(IntNode head,int position)测试 System.out.println("-------------------------"); try { System.out.println("Position 5: " + IntNode.listPosition(shortList,5).getData()); } catch (IllegalArgumentException e) { e.printStackTrace(); } } int data; IntNode link; public IntNode(int data,IntNode link) { this.data = data; this.link = link; } public int getData() { return this.data; } public void setData(int data) { this.data = data; } public IntNode getLink() { return this.link; } public void setLink(IntNode link) { this.link = link; } public void addNodeAfter(int element) { link = new IntNode(element,link); } public void removeNodeAfter() { link = link.link; } public static int listLength(IntNode head) { int answer = 0; IntNode cursor; if (head == null) { return answer; } for (cursor = head ; cursor != null ; cursor = cursor.getLink()) { answer++; } return answer; } public static IntNode listCopy(IntNode source) { IntNode copyHead = null; IntNode copyTail = null; if (source == null) { return null; } copyHead = new IntNode(source.getData(),null); copyTail = copyHead; while ((source = source.getLink()) != null) //书上代码为：while(source.link != null) { IntNode copyTemp = new IntNode(source.getData(),copyTail.getLink()); copyTail.link = copyTemp; copyTail = copyTemp; // 上为自己构思的方法，这个相当于copyTail一直向后加 // 以下书上的源代码 //source = source.link; //copyTail.addNodeAfter(source.getData()); //copyTail = copyTail.getLink(); } return copyHead; } public static IntNode[] listCopyWithTail(IntNode source) { IntNode copyHead = null; IntNode copyTail = null; IntNode[] answer = new IntNode[2]; if (null == source) { return answer; } copyHead = new IntNode(source.getData(),null); copyTail = copyHead; answer[0] = copyHead; System.out.println("-----------------------------"); while ((source = source.getLink()) != null) { System.out.println("source data:" + source.getData()); //copyTail = new IntNode(source.getData(),copyTail.getLink()); copyTail.link = new IntNode(source.getData(),copyTail.getLink()); copyTail = copyTail.link; //copyTail.addNodeAfter(source.getData()); //copyTail = copyTail.getLink();; System.out.println("copyed Tail data:" + copyTail.getData()); } answer[1] = copyTail; return answer; } public static IntNode[] listPart(IntNode head,IntNode start,IntNode end) { IntNode copyHead; IntNode copyTail; IntNode[] answer = new IntNode[2]; if (null == start) { throw new IllegalArgumentException("start is null."); } if (null == end) { throw new IllegalArgumentException("end is null."); } copyHead = new IntNode(start.getData(),null); //System.out.println("start data: " + start.getData()); //System.out.println("end data: " + end.getData()); copyTail = copyHead; start = IntNode.listNodeByData(head,start.getData()); end = IntNode.listNodeByData(head,end.getData()); while (start != end) { start = start.getLink(); System.out.println("start data: " + start.getData()); if (null == start) { throw new IllegalArgumentException("end node was not found on the list."); } copyTail.link = new IntNode(start.getData(),copyTail.getLink()); copyTail = copyTail.link; } answer[0] = copyHead; answer[1] = copyTail; return answer; } public static int[] listData(IntNode head) { int[] answer = new int[IntNode.listLength(head)]; for (int i = 0; head != null ; head = head.link ) { answer[i++] = head.getData(); } return answer; } public static IntNode listNodeByData(IntNode head,int data) { if (null == head) { throw new IllegalArgumentException("list is null."); } for (; head != null ; head = head.getLink() ) { if (head.getData() == data ) { return head; } if (null == head) { throw new IllegalArgumentException("node not found."); } } return null; } public static IntNode listPosition(IntNode head,int position) { position--; if (null == head) { throw new IllegalArgumentException("list is null."); } if (position <= 0) { throw new IllegalArgumentException("position is not positive!"); } for (int i = 0 ; (i < position) && (head != null) ; i++ ) { head = head.getLink(); } return head; } }