public string MiddleToPost() //中缀表达式转换为后缀表达式
{
char[] aa = middleExpression.ToCharArray();
int leng = aa.Length + 1;
MyStack <char> save = new MyStack <char>(leng);
save.Push('#');
char[] showCase = new char[aa.Length];
int showNum = 0;
for (int i = 0; i < aa.Length; i++)
{
if (CharJuddging(aa[i]) == "OPD")
{
showCase[showNum] = aa[i];
showNum++;
}
else if (aa[i] != '(' && aa[i] != ')')
{
if (CharComparing(aa[i], save.GetTop()) == 1 || save.GetTop() == '(')
{
save.Push(aa[i]);
}
else
{
while (CharComparing(aa[i], save.GetTop()) < 1)
{
showCase[showNum] = save.Pop();
showNum++;
}
save.Push(aa[i]);
}
}
else
{
if (aa[i] == '(')
{
save.Push(aa[i]);
}
else
{
while (save.GetTop() != '(')
{
showCase[showNum] = save.Pop();
showNum++;
}
save.Pop();
}
}
}
while (save.GetLength() > 1)
{
showCase[showNum] = save.Pop();
showNum++;
}
string tt = new string(showCase);
return(tt);
}
static bool IsSymmetry(char[] xx) //判断是否为中心对称串的函数
{
int leng = xx.Length + 1;
MyStack <char> exam1 = new MyStack <char>(leng);
int a = xx.Length % 2;
if (a == 0)
{
for (int i = 0; i < xx.Length; i++)
{
if (i == 0 || (i > 0 && xx[i] != exam1.GetTop()))
{
exam1.Push(xx[i]);
}
else
{
exam1.Pop();
}
}
}
else
{
for (int i = 0; i < xx.Length; i++)
{
if (i == (xx.Length - 1) / 2)
{
continue;
}
else if (i == 0 || (i > 0 && xx[i] != exam1.GetTop()))
{
exam1.Push(xx[i]);
}
else
{
exam1.Pop();
}
}
}
if (exam1.IsEmpty())
{
return(true);
}
else
{
return(false);
}
}
