冒泡排序 bubble sorting
int t;
int[] a ={21,56,64,94,97,123};
for(int j =a.Length-1;j>0;j--)
{ for(int i =0;i<j;i++)
{ if(a[i]>a[i+1])
{ t =a[i];
a[i]=a[i+1];
a[i+1]=t;
} } }
for(int u =0;u<a.Length;u++)
Console.WriteLine(a[u]); 结果:21,56,64,94,97,123
同时找最大最小
int temp;
int[] a={56,66,5,1230,87,95};
for(int i =0;i<(a.Length+1)/2;i++)
{ if(a[i]>a[a.Length-1-i])
{ temp =a[i];
a[i] =a[a.Length-1-i];
a[a.Length-1-i] =temp;
}
}
int max =a[a.Length-1],min =a[0];
for(int i=0;i<(a.Length+1)/2;i++)
{ if(min>a[i])
min =a[i];
}
for(int i =(a.Length+1)/2;i<a.Length;i++)
{ if(max<a[i])
max =a[i];
}
Console.WriteLine("{0},{1}",min,max); 结果：5,1230
基数排序
int[] a={1,5,9,7};
int[] b=new int[10];
for(int i=0;i<a.Length;i++)
b[a[i]]=1;
for(int j=0;j<b.Length;j++)
if(b[j]==1)
Console.WriteLine(j); 结果：1,5,7,9
插入排序
int[] r={12,2,6,65,42};
for(int i=1;i<r.Length;i++)
{ int t;
t=r[i];
int j;
for(j=i-1;j>=0 && r[j]>t;j--)
{}
for(int k=i;k>j+1;k--)
r[k]=r[k-1];
r[j+1]=t;
}
for(int f=0;f<r.Length;f++)
Console.WriteLine(r[f]); 结果：2,6,12,42,65
QuickSort 快速排序
static void QuickSort(int[] a,int start,int end)
{ int i=start,j=end;
int pivot = a[i];
while(i<j)
{ while(i<j && pivot<=a[j])
j--;
a[i] = a[j];
while(i<j && a[i]<=pivot)
i++;
a[j]=a[i];
}
a[i] = pivot;
if(i>start)
QuickSort(a,start,i);
if(i<end)
QuickSort(a,i+1,end);
}
static void Main(string[] args)
{ int[] x={87,56,5,13,5,12,};
QuickSort(x,0,x.Length-1);
for(int i=0;i<x.Length;i++)
Console.WriteLine(x[i]);
} 结果：5,5,12,13,56,87
MergeSort 归并排序
static void MergeSort(int[] a,int s,int e)
{ if(s>=e) return;
MergeSort(a,s,(s+e)/2);
MergeSort(a,(s+e)/2+1,e);
Merge(a,s,(s+e)/2,e);
}
static void Merge(int[] a,int s,int mid, int e)
{ int[] b=new int[a.Length];
for(int w=0;w<a.Length;w++)
b[w]=a[w];
int i=s;
int j=mid+1;
int k=s;
while(i<=mid && j<=e)
{ if(b[i]<b[j])
a[k++] = b[i++];
else
a[k++] = b[j++];
}
while(i<=mid)
a[k++] = b[i++];
while(j<=e)
a[k++] = b[j++];
}
static void Main(string[] args)
{ int[] a={34,2,5,66,87,99};
MergeSort(a,0,a.Length-1);
for(int i=0;i<a.Length;i++)
Console.WriteLine(a[i]);
} 结果:2,5,34,66,87,99
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();
} } } }
C#基础
ArrayList
ArrayList al;
al =new ArrayList();
string s = Console.ReadLine();
while(s !="q")
{ al.Add(s);
s = Console.ReadLine();
}
for(int i=0;i<al.Count;i++)
Console.WriteLine(al[i].ToString());
从键盘输入一个数组,并求最大
int[] a;
Console.WriteLine("Pls input len:");
int len = Convert.ToInt32(Console.ReadLine());
a = new int[len];
Console.WriteLine("Pls input array");
for(int i=0;i<len;i++)
{ a[i]=Convert.ToInt32(Console.ReadLine()); }
for(int j=0;j<a.Length;j++)
Console.WriteLine(a[j]);
for(int k=0;k<a.Length;k++)
{ if(a[0]<a[k])
a[0]=a[k];
} Console.WriteLine(a[0]);
递归
int fac (int n)
{ if(n==0) return 1;
return n*fac(n-1);
}
斐波那契数列第n项
int fib (int n)
{ if(n==1) return 1;
if(n==2) return 1;
return fib(n-1)+fib(n-2);
}
递归求1加到100
public int Fac(int n)
{ if(n==1) return 1;
return n+Fac(n-1);
}
static void Main()
{ math f=new math();
int s=f.Fac(100);
Console.WriteLine(s);
}
求前24项斐波那契序列数
static int fib(int n)
{ if(n==1) return 1;
if(n==2) return 1;
return fib(n-1)+fib(n-2);
}
static void Main(string[] args)
{ int t=0;
for(int i=1;i<25;i++)
{ t=fib(i);
Console.WriteLine(t);
} }
汉诺塔
static void Hanoi(string X, string Y,string Z,int n)
{ if(n==1)
{ Console.WriteLine(X + "-->" +Z);
return;
}
Hanoi (X,Z,Y,n-1);
Console.WriteLine(X+"-->"+Z);三
Hanoi (Y,X,Z,n-1);
}
static void Main(string[] args)
{ Hanoi("A","B","C",5); }
3位的水仙花数
for(int i=100;i<1000;i++)
{ int a=i/100; int c=i; int b=((i-c)/10);
if(i==a*a*a+b*b*b+c*c*c)
Console.WriteLine(i);
}
StringBuilder
class A
{ static void Main()
{ StringBuilder a=new StringBuilder();
a.Append ("asa");
a.Append ("www");
string s=a.ToString();
Console.WriteLine(s);
}
} 结果:asawww
singleton设计模式
class A
{ private int v;
A(int x)
{ v=x; }
public int V
{ get{return v;} }
static A c=null;
public static A fun(int n)
{ if(c==null)
c=new A(n);
return c;
}
}
class B
{ static void Main(string[] args)
{ A c=A.fun(2);
Console.WriteLine(c.V);
c=A.fun(8);
Console.WriteLine(c.V);
}
} 结果：2,2