Java數(shù)據(jù)結(jié)構(gòu)之鏈表(動(dòng)力節(jié)點(diǎn)之Java學(xué)院整理)

更新時(shí)間：2017年04月14日 10:01:29 投稿：mrr

這篇文章主要介紹了Java數(shù)據(jù)結(jié)構(gòu)之鏈表(動(dòng)力節(jié)點(diǎn)之Java學(xué)院整理)的相關(guān)資料,需要的朋友可以參考下

單鏈表：

insertFirst：在表頭插入一個(gè)新的鏈接點(diǎn)，時(shí)間復(fù)雜度為O(1)

deleteFirst：刪除表頭的鏈接點(diǎn)，時(shí)間復(fù)雜度為O(1)

find：查找包含指定關(guān)鍵字的鏈接點(diǎn)，由于需要遍歷查找，平均需要查找N/2次，即O(N)

remove：刪除包含指定關(guān)鍵字的鏈接點(diǎn)，由于需要遍歷查找，平均需要查找N/2次，即O(N)

public class LinkedList { 
   private class Data{ 
     private Object obj; 
     private Data next = null;       
     Data(Object obj){ 
       this.obj = obj; 
     } 
   } 
   private Data first = null; 
    
   public void insertFirst(Object obj){ 
     Data data = new Data(obj); 
     data.next = first; 
     first = data; 
   } 
   public Object deleteFirst() throws Exception{ 
     if(first == null) 
       throw new Exception("empty!"); 
     Data temp = first; 
     first = first.next; 
     return temp.obj; 
   }     
   public Object find(Object obj) throws Exception{ 
     if(first == null) 
       throw new Exception("LinkedList is empty!"); 
     Data cur = first; 
     while(cur != null){ 
       if(cur.obj.equals(obj)){ 
         return cur.obj; 
       } 
       cur = cur.next; 
     } 
     return null; 
   } 
   public void remove(Object obj) throws Exception{ 
     if(first == null) 
       throw new Exception("LinkedList is empty!"); 
     if(first.obj.equals(obj)){ 
       first = first.next; 
     }else{ 
       Data pre = first; 
       Data cur = first.next; 
       while(cur != null){ 
         if(cur.obj.equals(obj)){ 
           pre.next = cur.next; 
         } 
        pre = cur; 
         cur = cur.next; 
       } 
     } 
   } 
   public boolean isEmpty(){ 
     return (first == null); 
   } 
   public void display(){ 
     if(first == null) 
       System.out.println("empty"); 
     Data cur = first; 
     while(cur != null){ 
       System.out.print(cur.obj.toString() + " -> "); 
       cur = cur.next; 
     } 
     System.out.print("\n"); 
   }     
   public static void main(String[] args) throws Exception { 
     LinkedList ll = new LinkedList(); 
     ll.insertFirst(4); 
     ll.insertFirst(3); 
     ll.insertFirst(2); 
     ll.insertFirst(1); 
     ll.display(); 
     ll.deleteFirst(); 
     ll.display(); 
     ll.remove(3); 
     ll.display(); 
     System.out.println(ll.find(1)); 
     System.out.println(ll.find(4)); 
   } 
 }

 1 -> 2 -> 3 -> 4 ->  
 2 -> 3 -> 4 ->  
 2 -> 4 ->  
 null 
 4

雙端鏈表(不是雙向鏈表)：

與單向鏈表的不同之處在保存有對(duì)最后一個(gè)鏈接點(diǎn)的引用(last)

insertFirst：在表頭插入一個(gè)新的鏈接點(diǎn)，時(shí)間復(fù)雜度O(1)

insertLast：在表尾插入一個(gè)新的鏈接點(diǎn)，時(shí)間復(fù)雜度O(1)

deleteFirst：刪除表頭的鏈接點(diǎn)，時(shí)間復(fù)雜度O(1)

deleteLast:：刪除表尾的鏈接點(diǎn)，由于只保存了表尾的鏈接點(diǎn)，而沒(méi)有保存表尾的前一個(gè)鏈接點(diǎn)(這里就體現(xiàn)出雙向鏈表的優(yōu)勢(shì)了)，所以在刪除表尾鏈接點(diǎn)時(shí)需要遍歷以找到表尾鏈接點(diǎn)的前一個(gè)鏈接點(diǎn)，需查找N-1次，也就是O(N)
有了這幾個(gè)方法就可以用雙端鏈表來(lái)實(shí)現(xiàn)一個(gè)隊(duì)列了

 public class FirstLastList { 
   private class Data{ 
     private Object obj; 
     private Data next = null;       
     Data(Object obj){ 
       this.obj = obj; 
     } 
   }     
   private Data first = null; 
   private Data last = null;     
   public void insertFirst(Object obj){ 
     Data data = new Data(obj); 
     if(first == null) 
       last = data; 
     data.next = first; 
     first = data; 
   }     
   public void insertLast(Object obj){ 
     Data data = new Data(obj); 
     if(first == null){ 
       first = data; 
     }else{ 
       last.next = data;   
     } 
     last = data; 
   }     
   public Object deleteFirst() throws Exception{ 
      if(first == null) 
       throw new Exception("empty"); 
      Data temp = first; 
      if(first.next == null) 
       last = null; 
      first = first.next; 
      return temp.obj; 
  }   
   public void deleteLast() throws Exception{ 
     if(first == null) 
       throw new Exception("empty"); 
     if(first.next == null){ 
       first = null; 
       last = null; 
     }else{ 
       Data temp = first; 
       while(temp.next != null){ 
         if(temp.next == last){ 
           last = temp; 
           last.next = null; 
           break; 
        } 
        temp = temp.next; 
      } 
     } 
   } 
   public void display(){ 
     if(first == null) 
       System.out.println("empty"); 
     Data cur = first; 
     while(cur != null){ 
       System.out.print(cur.obj.toString() + " -> "); 
       cur = cur.next; 
     } 
     System.out.print("\n"); 
   } 
   public static void main(String[] args) throws Exception { 
     FirstLastList fll = new FirstLastList(); 
     fll.insertFirst(2); 
     fll.insertFirst(1); 
     fll.display(); 
     fll.insertLast(3); 
     fll.display(); 
     fll.deleteFirst(); 
     fll.display(); 
     fll.deleteLast(); 
     fll.display(); 
   } 
 }

 1 -> 2 ->  
 1 -> 2 -> 3 ->  
 2 -> 3 ->  
 2 ->

有序鏈表：

鏈表中的數(shù)據(jù)按從小到大排列

public class SortedList { 
   private class Data{ 
     private Object obj; 
     private Data next = null;       
     Data(Object obj){ 
       this.obj = obj; 
     } 
   }   
   private Data first = null;     
   public void insert(Object obj){ 
     Data data = new Data(obj); 
     Data pre = null; 
     Data cur = first; 
     while(cur != null && (Integer.valueOf(data.obj.toString()) 
        .intValue() > Integer.valueOf(cur.obj.toString()) 
         .intValue())){ 
       pre = cur; 
      cur = cur.next; 
     } 
     if(pre == null) 
       first = data; 
     else 
       pre.next = data; 
     data.next = cur; 
   }     
   public Object deleteFirst() throws Exception{ 
     if(first == null) 
       throw new Exception("empty!"); 
     Data temp = first; 
     first = first.next; 
     return temp.obj; 
   }     
   public void display(){ 
     if(first == null) 
       System.out.println("empty"); 
     System.out.print("first -> last : "); 
     Data cur = first; 
     while(cur != null){ 
       System.out.print(cur.obj.toString() + " -> "); 
       cur = cur.next; 
     } 
     System.out.print("\n"); 
   }     
   public static void main(String[] args) throws Exception{ 
     SortedList sl = new SortedList(); 
     sl.insert(80); 
     sl.insert(2); 
     sl.insert(100); 
     sl.display(); 
     System.out.println(sl.deleteFirst()); 
     sl.insert(33); 
     sl.display(); 
     sl.insert(99); 
     sl.display(); 
   } 
 }

 first -> last : 2 -> 80 -> 100 ->  
 2 
 first -> last : 33 -> 80 -> 100 ->  
 first -> last : 33 -> 80 -> 99 -> 100 ->

表的插入和刪除平均需要比較N/2次，即O(N)，但是獲取最小數(shù)據(jù)項(xiàng)只需O(1)，因?yàn)槠涫冀K處于表頭，對(duì)頻繁操作最小數(shù)據(jù)項(xiàng)的應(yīng)用，可以考慮使用有序鏈表實(shí)現(xiàn)，如：優(yōu)先級(jí)隊(duì)列和數(shù)組相比，鏈表的優(yōu)勢(shì)在于長(zhǎng)度不受限制，并且在進(jìn)行插入和刪除操作時(shí)，不需要移動(dòng)數(shù)據(jù)項(xiàng)，故盡管某些操作的時(shí)間復(fù)雜度與數(shù)組想同，實(shí)際效率上還是比數(shù)組要高很多。劣勢(shì)在于隨機(jī)訪問(wèn)，無(wú)法像數(shù)組那樣直接通過(guò)下標(biāo)找到特定的數(shù)據(jù)項(xiàng) 。

以上所述是小編給大家介紹的Java數(shù)據(jù)結(jié)構(gòu)之鏈表(動(dòng)力節(jié)點(diǎn)之Java學(xué)院整理)，希望對(duì)大家有所幫助，如果大家有任何疑問(wèn)請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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