C#算法，二叉树，单链表，反向链表，stack栈
二叉查找树
// 二叉查找树节点 Binary search tree node
public class BinarySearchTreeNode
{ public int key;// 二叉查找树节点的值
public BinarySearchTreeNode left;// 二叉查找树节点的左子节点
public BinarySearchTreeNode right;// 二叉查找树节点的右子节点
/// 二叉查找树节点构造函数
public BinarySearchTreeNode(int nodeValue)
{ key = nodeValue;//nodeValue 节点的值
left = null; right = null;
}
/// 插入节点
public void InsertNode(BinarySearchTreeNode node)
{ if(node.key > this.key)
{ if(this.right == null)
{ this.right = node;//node插入的节点
return;
}
else
this.right.InsertNode(node);
}
else
{ if(this.left == null)
{ this.left = node; return; }
else
this.left.InsertNode(node);
}
}
/// 二叉查找树查询
public bool SearchKey(int searchValue)
{ if(this.key == searchValue)//searchValue需要查询的值
return true;// 是否找到查询的值
if(searchValue > this.key)
{ if(this.right == null) return false;
else
return this.right.SearchKey(searchValue);
}
else
{ if(this.left == null) return false;
else
return this.left.SearchKey(searchValue);
}
}
// 中序遍历
public void MiddleDisplay()
{ if(this.left != null)
this.left.MiddleDisplay();
Console.WriteLine(this.key);
if(this.right != null)
this.right.MiddleDisplay();
}
// 前序遍历
public void FrontDisplay()
{ Console.WriteLine(this.key);
if(this.left != null)
this.left.FrontDisplay();
if(this.right != null)
this.right.FrontDisplay();
}
// 后序遍历
public void BehindDisplay()
{ if(this.left != null)
this.left.BehindDisplay();
if(this.right != null)
this.right.BehindDisplay();
Console.WriteLine(this.key);
}
}
/// 二叉查找树
public class BinarySearchTree
{ private BinarySearchTreeNode root;
/// 生成一个二叉查找树
public BinarySearchTree()
{ root = nul; }
/// 生成一个二叉查找树
/// <param name="nodeValue">二叉查找树根节点的值</param>
public BinarySearchTree(int nodeValue)
{ root = new BinarySearchTreeNode(nodeValue); }
/// 在二叉查找树上插入一个节点
/// <param name="nodeValue">插入节点的值</param>
public void InsertBinarySearchTreeNode(int nodeValue)
{ BinarySearchTreeNode insertNode = new BinarySearchTreeNode(nodeValue);
if(root == null)
{ root = insertNode;
return;
}
else
root.InsertNode(insertNode);
return;
}
/// 在二叉查找树上查询一个数
/// <param name="searchValue">需要查询的值</param>
/// <returns>是否找到查询的值</returns>
public bool SearchKey(int searchValue)
{ if(root.key == searchValue) return true;
else
return root.SearchKey(searchValue);
}
/// 二叉查找树中序遍历
public void MiddleDisplay()
{ root.MiddeleDisplay(); return; }
/// 二叉查找树前序遍历
public void FrontDisplay()
{ root.FrontDisplay(); return; }
/// 二叉查找树后序遍历
public void BehindDisplay()
{ root.BehindDisplay(); return; }
/// 二叉查找树排序
/// <param name="a">需要排序的数组</param>
public static void BinarySearchTreeSort(int [] a)
{ BinarySearchTree t = new BinarySearchTree();
for(int i = 0; i < a.Length; i ++)
t.InsertBinarySearchTreeNode(a[i]);
t.MiddleDisplay();return;
}/// 二叉查找树查找
/// <param name="a">进行查找的数组</param>
/// <param name="searchKey">需要查找的树</param>
public static bool BinarySearchTreeSearch(int [] a, int searchKey)
{ BinarySearchTree t = new BinarySearchTree();
for(int i = 0; i < a.Length; i ++)
t.InsertBinarySearchTreeNode(a[i]);
return t.SearchKey(searchKey);
}
}
namespace 二叉树
{ class Node
{ int n;
public Node(int x)
{ n=x; }
public Node Left;
public Node Right;
public void Insert(Node node)
{ if(node.n > this.n)
{ if(this.Right == null)
this.Right = node;
else
this.Right.Insert(node); }
else
{ if(this.Left == null)
{ this.Left = node; }
else
{ this.Left.Insert(node); } } } //递归
public void Show()
{ Console.WriteLine(n); } }
class BinaryTree
{ Node root;
public void GenerateTree(Node node) //高内聚，低耦合
{ if(root == null)
{ root = node; return; }//如果树是空，第一次加节点
root.Insert(node);
}
public void ShowInOrder(Node node) //中序遍历(in order)：左中右。先(前)序遍历(pre order)：中左右。后序遍历(post order)：左右中。
{ if(node == null) return;//递归必须有个终止条件,递归方法中一定要接受参数
ShowInOrder(node.Left);
node.Show();
ShowInOrder(node.Right);
}
public void Show()
{ ShowInOrder(root); }
}
class A
{ static void Main()
{ BinaryTree b = new BinaryTree();
Node node = new Node(5);
b.GenerateTree(node);
node = new Node(13);
b.GenerateTree(node);
node = new Node(6);
b.GenerateTree(node);
node = new Node(26);
b.GenerateTree(node);
node = new Node(7);
b.GenerateTree(node);
b.Show(); } } } 结果:5,6,7,13,26
单链表
class Node
{ int a;
public Node(int a)
{ this.a=a; }
public int A
{get{return a;} set{a=value;} }
public Node next;
}
class LinkedList
{ Node header;
public void Generate(int x)
{ if(header==null)
header=new Node(x);
else
{ Node n = new Node(x);
if(n.A < header.A)
{ n.next = header;
header=n;
return;
}
Node tmp=header;
Node t=header;
while(tmp.A < n.A)
{ t=tmp; //为了下一次循环
tmp=tmp.next;
if(tmp==null)
break;
}
t.next=n;
n.next=tmp;
}
}
public void Out()
{ Node tmp=header;
while(tmp!=null)
{ Console.WriteLine(tmp.A);
tmp = tmp.next;
} } }
class Test
{ static void Main()
{ LinkedList ll = new LinkedList();
ll.Generate(6);
ll.Generate(36);
ll.Generate(26);
ll.Generate(16);
ll.Out();
} } }
反向链表
class Link //this class reverse the LinkedList
{ public int a;
public Link next;
}
class createLink //the class create the LinkedList
{
Link header=null;
Link p = null;
Link temp = null;
Link l=null; //Link k=null;
Link g=null;
public void create()
{ string str;
int i;
Console.WriteLine("Please enter number:");
str=Console.ReadLine();
while(str!="y")
{ i=Convert.ToInt32(str);
temp=new Link();
temp.a=i;
temp.next=null;
if(g==null)
g=temp;
if(header==null)
header=temp;
if(p==null)
p=temp;
else
{ p.next=temp;
p=p.next;
}
Console.WriteLine("please enter number:");
str=Console.ReadLine();
}
}
public void display()
{ while(header!=null)
{ Console.WriteLine(header.a);
header=header.next;
}
}
public void reversed() // the mothod reversed the LinkedList
{ Link k=null;
Link tmp=null;
Link com =null;
if(tmp==null)
tmp=header.next;
while(tmp!=null)
{ // if(com==null)
// com=header;
l=tmp;
if(k==null)
{ header.next=null;
k=header;
}
com=header;
header=l;
tmp=l.next;
l.next=com;
}
}
public void show()
{ while(l!=null)
{ Console.WriteLine(l.a);
l=l.next;
} } }
class Tester
{ static void Main()
{ createLink cl=new createLink();
cl.create();
//cl.display();
cl.reversed();
cl.show();
} } }
Stack 栈
class Node
{ int a;
public Node(int a)
{ this.a=a; }
public int A
{ get{return a;} set{a=value;} }
public Node next;
}
class LinkedList
{ protected Node header;
public void Generate(int x)
{ if(header==null)
header=new Node(x);
else
{ Node n = new Node(x);
n.next=header;
header=n;
}
}
public void Out()
{ Node tmp=header;
while(tmp!=null)
{ Console.WriteLine(tmp.A);
tmp = tmp.next;
} } }
class Stack : LinkedList
{ public void Push(int x)
{ this.Generate(x); }
public int Pop()
{ if(this.header == null)
return -1; // empty stack
int n = header.A;
header = header.next;
return n;
}
}
class Test
{ static void Main()
{ Stack ss = new Stack();
ss.Push(7);
ss.Push(78);
ss.Push(9);
ss.Push(2);
int i = ss.Pop();
while(i != -1)
{ Console.WriteLine(i);
i = ss.Pop();
} } } }
