public int Eval()
{
SequencedStack <int> stack = new SequencedStack <int>();
int i = 0;
char ch;
string num = "";
while (i < pstr.Length)
{
ch = pstr[i];
if ((ch >= '0') && (ch <= '9'))//遇到数字就入栈
{
num = "";
while (ch != ' ')
{
num += ch;
i++;
if (i < pstr.Length)
{
ch = pstr[i];
}
}
stack.Push(int.Parse(num));
i++;
}
else if ((ch == '+') || (ch == '-') || (ch == '*') || (ch == '/')) //遇到运算符，出栈两个数字进行运算
{
int a, b; //注意两个元素的先后顺序
a = stack.Pop();
b = stack.Pop();
switch (ch)
{
case '+':
stack.Push(b + a);
break;
case '-':
stack.Push(b - a);
break;
case '*':
stack.Push(b * a);
break;
case '/':
stack.Push(b / a);
break;
default:
break;
}
i++;
}
else
{
i++;
}
}
return(stack.Pop());
}
public static void Main(string[] args)
{
SequencedQueue <int> queue = new SequencedQueue <int>();
SequencedStack <int> stack = new SequencedStack <int>();
int length = 0;
queue.Enqueue(10);
queue.Enqueue(20);
queue.Enqueue(30);
queue.Enqueue(50);
queue.Enqueue(50);
queue.Enqueue(60);
Console.WriteLine("The num in original order:");
length = queue.Count;
for (int i = 0; i < length; i++)
{
int temp = queue.Dequeue();
Console.Write(temp + " ");
stack.Push(temp);
}
Console.WriteLine();
Console.WriteLine("The num in reverse order:");
length = stack.Count;
for (int i = 0; i < length; i++)
{
Console.Write(stack.Pop() + " ");
}
Console.WriteLine();
}
public bool isMatchBacket()
{
bool isMatch = false;
SequencedStack <char> stack = new SequencedStack <char>();
int i = 0;
while (i < expstr.Length)
{
if (expstr[i] == '(')
{
stack.Push('(');
}
else if (expstr[i] == ')')
{
if (stack.Empty)
{
return(false);
}
else
{
if (stack.Peek() == '(')
{
stack.Pop();
}
}
}
i++;
}
isMatch = stack.Empty;
return(isMatch);
}
static void Main(string[] args)
{
SequencedQueue <int> sequencedqueue = new SequencedQueue <int>(NUM);
SequencedStack <int> sequencedstack = new SequencedStack <int>(NUM);
//以下for可以合并为1个
//将数字放入队列并显示
for (int i = 0; i < NUM; i++)
{
sequencedqueue.Enqueue(i);
}
Console.Write("原来的队列： ");
sequencedqueue.Show(false);
//将队列元素依次入栈
for (int i = 0; i < NUM; i++)
{
sequencedstack.Push(sequencedqueue.Dequeue());
}
foreach (var item in sequencedstack.Elements)
{
Console.Write("{0} ", item);
}
//将栈元素依次弹出到队列
for (int i = 0; i < NUM; i++)
{
sequencedqueue.Enqueue(sequencedstack.Pop());
}
Console.Write("反序后队列： ");
sequencedqueue.Show(false);
}
public static void Main(string[] args)
{
SequencedStack <int> num = new SequencedStack <int>();
int decimal_num = default(int), length;
StringBuilder Hex_num = new StringBuilder();
Console.Write("Please input a num in decimal:");
try
{
decimal_num = int.Parse(Console.ReadLine());
}
catch (FormatException e)
{
Console.WriteLine("Please input a num in decimal!!! " + e.GetType());
}
while (decimal_num > 0)
{
num.Push(decimal_num % 16);
decimal_num /= 16;
}
//由于栈的长度会随着Pop()的调用而变化,所以需要一个变量保存
length = num.Count;
for (int i = 0; i < length; i++)
{
Hex_num.Append(Num2Str(num.Pop()));
}
Console.WriteLine(Hex_num);
}
/// <summary>
/// <para>使用自定义栈SequencedStack进行10进制到16进制转换</para>
/// </summary>
private static void trofSequencedStack(int num)
{
//由于初始化为10位：故最大只能转换10位的16进制数
SequencedStack <int> sequencedstack = new SequencedStack <int>(10);
Console.WriteLine("转换前的十进制整数： {0}", num);
while (num != 0)
{
sequencedstack.Push(num % 16);
num = num / 16;
}
int i = sequencedstack.Count;
Console.Write("转换后的十六进制整数： ");
for (; i > 0; i--)
{
if (sequencedstack.Peek() < 10)
{
Console.Write(sequencedstack.Pop() + "");
}
else
{
switch (sequencedstack.Pop())
{
case 10: Console.Write("A"); break;
case 11: Console.Write("B"); break;
case 12: Console.Write("C"); break;
case 13: Console.Write("D"); break;
case 14: Console.Write("E"); break;
case 15: Console.Write("F"); break;
default: break;
}
}
}
Console.WriteLine();
}
/// <summary>
/// 判断表达式括号是否匹配（中序表达式）
/// </summary>
public static string MatchingBracket(string expstr)
{
SequencedStack <char> ss = new SequencedStack <char>(30);
char nextToken, outToken;
int i = 0;
bool LlrR = true;
while (LlrR && i < expstr.Length)
{
nextToken = expstr[i];
i++;
switch (nextToken)
{
//遇到 ( ,将其入栈
case '(':
ss.Push(nextToken);
break;
//遇到 ) ,弹出栈顶元素
case ')':
if (ss.Empty)
{
LlrR = false;
}
else
{
outToken = ss.Pop();
//遇到 ( ，但出栈的不是 )
if (!outToken.Equals('('))
{
LlrR = false;
}
}
break;
}
}
if (LlrR)
{
return(ss.Empty ? "OK!": "期望)!");
}
else
{
return("期望(!");
}
}
/// <summary>
/// 将输入的中序表达式转换为后序表达式
/// <para>1.从左到右对中缀表达式进行扫描，每次处理一个字符</para>
/// <para>2.遇到左括号，入栈；遇到数字，原样输出</para>
/// <para>3.遇到常规运算符时：</para>
/// <para>①栈非空 且栈顶不是左括号 且栈顶运算符的优先级不低于输入运算符优先级，</para>
/// <para>反复将栈顶元素出栈输出</para>
/// <para>②当不符合①时则把输入的运算符压栈</para>
/// <para>4.若遇到右括号，则运算符出栈，直到出栈的数据元素为左括号停止</para>
/// <para>5.当表达式的符号序列全部读入后，若栈内仍有元素，把他们依次出栈输出</para>
/// </summary>
public static string ConvertExp(String infixStr)
{
//创建长度为30的线性字符串栈
SequencedStack <string> ss = new SequencedStack <string>(30);
char ch;
string tempStr = "";
string postfixStr = "";
int i = 0;
//当表达式还没有读取结束时
while (i < infixStr.Length)
{
ch = infixStr[i];
switch (ch)
{
//当遇到 ＋ - 时（优先级低）
case '+':
case '-':
//栈非空且栈顶不是 ( 且栈顶运算符的优先级不低于输入的运算符的优先级时
//反复将栈顶元素出栈输出直到不符合上述条件
while (!ss.Empty && !(ss.Peek()).Equals("("))
{
tempStr = ss.Pop();
postfixStr += tempStr;
}
ss.Push(ch.ToString());
i++;
break;
//遇到 * / 时 （优先级高）
case '*':
case '/':
//它的优先级比栈顶数据元素的优先级相同，所以栈顶数据元素出栈
//直到新栈顶数据元素的优先级比它低，然后将它入栈
while (!ss.Empty && ((ss.Peek()).Equals("*") ||
(ss.Peek()).Equals("/")))
{
tempStr = ss.Pop();
postfixStr += tempStr;
}
ss.Push(ch.ToString());
i++;
break;
case '(':
//遇到左括号时, 入栈（优先级最高）
ss.Push(ch.ToString());
i++;
break;
case ')':
//遇到右括号时，栈顶元素出栈
//直到出栈的数据元素为左括号，此时才括号匹配
tempStr = ss.Pop();
while (!ss.Empty && (tempStr == null || !tempStr.Equals("(")))
{
postfixStr += tempStr;
tempStr = ss.Pop();
}
i++;
break;
default:
//遇到数字时（根据ASCII比较大小）
while (ch >= '0' && ch <= '9')
{
postfixStr += ch;
i++;
if (i < infixStr.Length)
{
ch = infixStr[i];
}
else
{
ch = '=';
}
}
// 添加分隔符使表达式美观
postfixStr += " ";
break;
}
}
while (!ss.Empty)
{
tempStr = ss.Pop();
postfixStr = postfixStr + tempStr;
}
return(postfixStr);
}
public string Transform()
{
pstr.Clear();
SequencedStack <char> stack = new SequencedStack <char>();
int i = 0;
char ch, temp;
while (i < expstr.Length)
{
ch = expstr[i];
switch (ch)
{
case '+':
case '-':
while ((!stack.Empty) && (stack.Peek() != '('))
{
temp = stack.Pop();
pstr.Append(temp);
}
pstr.Append(' ');
stack.Push(ch);
i++;
break;
case '*':
case '/':
while ((!stack.Empty) && ((stack.Peek() == '*') || (stack.Peek() == '/')))
{
temp = stack.Pop();
pstr.Append(temp);
}
pstr.Append(' ');
stack.Push(ch);
i++;
break;
case '(':
stack.Push(ch);
i++;
break;
case ')':
while ((!stack.Empty) && (stack.Peek() != '('))
{
temp = stack.Pop();
pstr.Append(temp);
}
stack.Pop();
i++;
break;
case '0': //数字
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
while ((ch >= '0') && (ch <= '9'))
{
pstr.Append(ch);
i++;
if (i < expstr.Length)
{
ch = expstr[i];
}
else
{
ch = '=';
}
}
pstr.Append(' ');
break;
default:
i++;
break;
}
}
while (!stack.Empty)
{
pstr.Append(stack.Pop());
//pstr.Append(' ');
}
return(pstr.ToString());
}