本章节为习题1.3.18-1.3.28的答案
删除x的后续结点。
public class ex1_3_18 {
/*public*/public static class Node{
//否则所写的内部类为动态的，而主程序是public static class main
//在java中，类中的静态方法不能直接调用动态方法，只有将某个内部类修饰为静态类，然后才能够在静态类中调用该类的成员变量和成员方法
String item;
Node next;
}
public static void delete(Node first){//static 总是忘记啊
//java中静态类不能调用动态的方法
if(first == null){
System.out.println("wrong!");
}
else{
while(first.next.next != null){
first = first.next;
}
first.next.item = null;
first.next = null;
}
}
public static void exhibition(Node first){
if(first == null){
System.out.println("zero");
}
else{
do{
System.out.print(first.item);
first = first.next;
}while(first != null);//竟然不是first.next
}
}
public static void main(String[] args) {
Node first = new Node();
Node second = new Node();
Node third = new Node();
//first.item = 'to';无效的字符常数 invalid character constant
//双引号不要写成单引号了
first.item = "i";
second.item = "am";
third.item = "poor";
first.next = second;
second.next = third;
exhibition(first);
System.out.println(" ");
delete(first);
exhibition(first);
}
}
import edu.princeton.cs.algs4.StdOut;
public class ex1_3_19 {
public static class Node{
String item;
Node next;
}
public static void exhibition(Node first){
Node current = first;
if(current == null){
StdOut.print("zero!");
}
else{
do{
StdOut.print(current.item);
current = current.next;
}while(current != null);
}
}
public static void delete(Node first,int k)
{
// deal with k <= 0, list is empty
if (k <= 0 || first == null) return;
// deal with first node
if (k == 1)
{
first = first.next;
return;
}
// make current equals k-1 node
k--;
Node current = first;
while (current != null && --k != 0)
{
current = current.next;
}
// list length less than k
if (k != 0 || current == null || current.next == null)
{
return;
}
else
{
current.next = current.next.next;
}
}
public static void main(String[] args) {
Node first = new Node();
Node second = new Node();
Node third = new Node();
Node forth = new Node();
first.item = "to";
second.item = "or";
third.item = "not";
forth.item = "is";
first.next = second;
second.next = third;
third.next = forth;
exhibition(first);
System.out.println(" ");
delete(first,2);
exhibition(first);
}
}
import edu.princeton.cs.algs4.StdOut;
public class ex1_3_20 {
public static class Node{
String item;
Node next;
}
public static void exhibition(Node first){
Node current = first;
if(current == null){
StdOut.print("zero!");
}
else{
do{
StdOut.print(current.item);
current = current.next;
}while(current != null);
}
}
public static boolean delete(Node first,String key)
{
for(Node current = first;current.next != null;current = current.next){
if(current.item.equals(key))
return true;//小写且拼写不要错
}
return false;//不要写到for循环里面，会导致函数没有返回值
}
public static void main(String[] args) {
Node first = new Node();
Node second = new Node();
Node third = new Node();
Node forth = new Node();
first.item = "to";
second.item = "or";
third.item = "not";
forth.item = "is";
first.next = second;
second.next = third;
third.next = forth;
exhibition(first);
System.out.println(" ");
delete(first,"not");
exhibition(first);
}
}
插入结点t，并使它成为x的后续结点
在更新t.next时，x.next已经不再指向x的后续结点，而是指向t本身！
明日继续补~
