C#实现的算24点游戏算法实例分析

本文实例讲述了c#实现的算24点游戏算法。分享给大家供大家参考。具体如下：

using system;
using system.collections.generic;
using system.linq;
using system.text;
using system.io;
namespace calc24points
{
 public class cell
 {
  public enum type
  {
   number,
   signal
  }
  public int number;
  public char signal;
  public type typ;
  public cell right;
  public cell left;
  /// <summary>
  /// 符号优先级
  /// </summary>
  public int priority
  {
   get
   {
    if (typ == type.signal)
    {
     switch (signal)
     {
      case '+': return 0;
      case '-': return 0;
      case '*': return 1;
      case '/': return 1;
      default: return -1;
     }
    }
    return -1;
   }
  }
  /// <summary>
  /// 基本单元构造函数
  /// </summary>
  /// <param name="t">单元类型，数值或符号</param>
  /// <param name="num">数值</param>
  /// <param name="sig">符号</param>
  public cell(type t, int num, char sig)
  {
   right = null;
   left = null;
   typ = t;
   number = num;
   signal = sig;
  }
  public cell()
  {
   right = null;
   left = null;
   number = 0;
   typ = type.number;
  }
  public cell(cell c)
  {
   right = null;
   left = null;
   number = c.number;
   signal = c.signal;
   typ = c.typ;
  }
 }
 public class calc24points
 {
  string m_exp;
  bool m_stop;
  cell[] m_cell;
  int[] m_express;
  stringwriter m_string;
  public calc24points(int n1, int n2, int n3, int n4)
  {
   m_cell = new cell[8];
   m_cell[0] = new cell(cell.type.number, n1, '?');
   m_cell[1] = new cell(cell.type.number, n2, '?');
   m_cell[2] = new cell(cell.type.number, n3, '?');
   m_cell[3] = new cell(cell.type.number, n4, '?');
   m_cell[4] = new cell(cell.type.signal, 0, '+');
   m_cell[5] = new cell(cell.type.signal, 0, '-');
   m_cell[6] = new cell(cell.type.signal, 0, '*');
   m_cell[7] = new cell(cell.type.signal, 0, '/');
   m_stop = false;
   m_express = new int[7];
   m_string = new stringwriter();
   m_exp = null;
  }
  public override string tostring()
  {
   if (m_exp == null)
   {
    putcell(0);
    m_exp = m_string.tostring();
   }
   if (m_exp != "") return m_exp;
   return null;
  }
  /// <summary>
  /// 在第n位置放置一个单元
  /// </summary>
  /// <param name="n"></param>
  void putcell(int n)
  {
   if (n >= 7)
   {
    if (calculate())
    {
     m_stop = true;
     formate();
    }
    return;
   }
   int end = 8;
   if (n < 2) end = 4;
   for (int i = 0; i < end; ++i)
   {
    m_express[n] = i;
    if (checkcell(n)) putcell(n + 1);
    if (m_stop) break;
   }
  }
  /// <summary>
  /// 检查当前放置是否合理
  /// </summary>
  /// <param name="n"></param>
  /// <returns></returns>
  bool checkcell(int n)
  {
   int nums = 0, sigs = 0;
   for (int i = 0; i <= n; ++i)
   {
    if (m_cell[m_express[i]].typ == cell.type.number) ++nums;
    else ++sigs;
   }
   if (nums - sigs < 1) return false;
   if (m_cell[m_express[n]].typ == cell.type.number)
   //数值不能重复，但是符号可以重复
   {
    for (int i = 0; i < n; ++i) if (m_express[i] == m_express[n]) return false;   
   }
   if (n == 6)
   {
    if (nums != 4 || sigs != 3) return false;
    if (m_cell[m_express[6]].typ != cell.type.signal) return false;
    return true;
   }
   return true;
  }
  /// <summary>
  /// 计算表达式是否为24
  /// </summary>
  /// <returns>返回值true为24，否则不为24</returns>
  bool calculate()
  {
   double[] dblstack = new double[4];
   int indexstack = -1;
   for (int i = 0; i < 7; ++i)
   {
    if (m_cell[m_express[i]].typ == cell.type.number)
    {
     ++indexstack;
     dblstack[indexstack] = m_cell[m_express[i]].number;
    }
    else
    {
     switch (m_cell[m_express[i]].signal)
     { 
      case '+':
       dblstack[indexstack - 1] = dblstack[indexstack - 1] + dblstack[indexstack];
       break;
      case '-':
       dblstack[indexstack - 1] = dblstack[indexstack - 1]-+ dblstack[indexstack];
       break;
      case '*':
       dblstack[indexstack - 1] = dblstack[indexstack - 1] * dblstack[indexstack];
       break;
      case '/':
       dblstack[indexstack - 1] = dblstack[indexstack - 1] / dblstack[indexstack];
       break;
     }
     --indexstack;
    }
   }
   if (math.abs(dblstack[indexstack] - 24) < 0.1) return true;
   return false;
  }
  /// <summary>
  /// 后缀表达式到中缀表达式
  /// </summary>
  void formate()
  {
   cell[] c = new cell[7];
   for (int i = 0; i < 7; ++i) c[i] = new cell(m_cell[m_express[i]]);
   int[] cstack = new int[4];
   int indexstack = -1;
   for (int i = 0; i < 7; ++i)
   {
    if (c[i].typ == cell.type.number)
    {
     ++indexstack;
     cstack[indexstack] = i;
    }
    else
    {
     c[i].right = c[cstack[indexstack]];
     --indexstack;
     c[i].left = c[cstack[indexstack]];
     cstack[indexstack] = i;
    }
   }
   tostringformate(c[cstack[indexstack]]);
  }
  void tostringformate(cell root)
  {
   if (root.left.typ == cell.type.number)
   {
    m_string.write(root.left.number);
    m_string.write(root.signal);
   }
   else
   {
    if (root.priority > root.left.priority)
    {
     m_string.write("(");
     tostringformate(root.left);
     m_string.write(")");
    }
    else tostringformate(root.left);
    m_string.write(root.signal);
   }
   if (root.right.typ == cell.type.number) m_string.write(root.right.number);
   else
   {
    if (root.priority >= root.right.priority)
    {
     m_string.write("(");
     tostringformate(root.right);
     m_string.write(")");
    }
    else tostringformate(root.right);
   }
  }
 }
}

希望本文所述对大家的c#程序设计有所帮助。