回文：字符对称排列的字符串，例如ABCBA
思路：根据队：先进先出和栈: 先进后出的原则，进行比较出队和出栈的字符是否相等。如果相等，则为回文。
创建控制台应用程序。
1 #region 字符节点类 2 class CharNode 3 { 4 public char Char //字符 5 { 6 get; 7 set; 8 } 9 public CharNode Next //下一节点 10 { 11 get; 12 set; 13 } 14 public CharNode(char Char,CharNode next) 15 { 16 this.Char = Char; 17 this.Next = next; 18 } 19 } 20 21 #endregion 22 23 #region 链队类 24 /// <summary> 25 /// 链队 26 /// </summary> 27 class CharQueue 28 { 29 CharNode front; //队头 30 CharNode rear; //队尾 31 /// <summary> 32 /// 进队 33 /// </summary> 34 /// <param name="Char">节点字符</param> 35 public void In(char Char) 36 { 37 if(rear==null) 38 { 39 rear= new CharNode(Char, null); //创建队头节点 40 front = rear; 41 } 42 else 43 { 44 rear.Next = new CharNode(Char, null); //创建队尾 45 rear = rear.Next; 46 } 47 } 48 49 /// <summary> 50 /// 出队 51 /// </summary> 52 /// <returns></returns> 53 public char? Out() 54 { 55 if(front==null) 56 { 57 return null; 58 } 59 60 char Char = front.Char; 61 front = front.Next; 62 if (front == null) 63 rear = null; 64 65 return Char; 66 67 } 68 69 } 70 #endregion 71 72 #region 链栈类 73 public class CharStack 74 { 75 CharNode top; 76 /// <summary> 77 /// 进栈 78 /// </summary> 79 /// <param name="Char">节点字符</param> 80 public void Push(char Char) 81 { 82 83 if(top==null) 84 { 85 top = new CharNode(Char, null); 86 } 87 else 88 { 89 top = new CharNode(Char, top); 90 } 91 } 92 /// <summary> 93 /// 出栈 94 /// </summary> 95 /// <returns></returns> 96 public char? Pop() //？代表可以返回null 97 { 98 if (this.top == null) 99 return null; 100 else 101 { 102 char Char = top.Char; 103 top = top.Next; 104 return Char; 105 } 106 } 107 } 108 109 #endregion 110 static void Main(string[] args) 111 { 112 Console.WriteLine("pls input one string:"); 113 string str = Console.ReadLine(); 114 CharStack stack = new CharStack(); //实例化栈 115 CharQueue queue = new CharQueue(); //实例化队 116 117 char? charStack, charQueue; 118 119 foreach(char Char in str) 120 { 121 queue.In(Char); //进队 122 stack.Push(Char); //进栈 123 } 124 125 do 126 { 127 charQueue = queue.Out(); //出队 128 charStack = stack.Pop(); //出栈 129 130 if (charQueue != charStack) 131 break; 132 } 133 while (charQueue != null && charStack != null); 134 135 if(charQueue!=null||charStack!=null) 136 { 137 Console.WriteLine("{0} is not 回文",str); 138 } 139 else 140 { 141 Console.WriteLine("{0} is 回文 ",str); 142 } 143 144 Console.ReadLine(); 145 146 }
