public string MidtoPosfix()
{
Stack <string> a = new Stack <string>();
string ketQuaHauTo = "";
string tokken;
string nhap = textBox1.Text;
nhap = nhap.Trim();
string s = "";
for (int i = 0; i < nhap.Length; i++)
{
if (nhap[i] != ' ')
{
s += nhap[i];
}
}
int demMoNgoac = 0;
int demDongNgoac = 0;
int demToanTu = 0;
int demToanHang = 0;
for (int i = 0; i < s.Length;)
{
GetTokken(s, out tokken, ref i);
if (tokken[0] == '(')
{
demMoNgoac++;
}
else if (tokken[0] == ')')
{
demDongNgoac++;
}
else if (LaToanTu(tokken[0]))
{
demToanTu++;
}
else
{
demToanHang++;
}
}
if (demDongNgoac == demMoNgoac && demToanHang - 1 == demToanTu)
{
for (int i = 0; i < s.Length;)
{
GetTokken(s, out tokken, ref i);
if (!LaToanTu(tokken[0]))
{
ketQuaHauTo += tokken + " ";
}
else
{
if (tokken[0] == '(')
{
a.Push(tokken);
}
else if (tokken[0] == ')')
{
while (a.Top()[0] != '(')
{
ketQuaHauTo += a.Top() + " ";
a.Pop();
}
if (a.Top()[0] == '(')
{
a.Pop();
}
}
else
{
if (!a.IsEmpty() && DoUuTien(a.Top()[0]) < DoUuTien(tokken[0]))
{
a.Push(tokken);
continue;
}
else if (a.IsEmpty())
{
a.Push(tokken);
continue;
}
while (!a.IsEmpty() && DoUuTien(a.Top()[0]) >= DoUuTien(tokken[0]))
{
ketQuaHauTo += a.Top() + " ";
a.Pop();
}
a.Push(tokken);
}
}
}
while (!a.IsEmpty())
{
if (a.Top()[0] == '(')
{
a.Pop();
continue;
}
ketQuaHauTo += a.Top() + " ";
a.Pop();
}
return(ketQuaHauTo);
}
else
{
return("\nBieu thuc sai");
}
}
//Vaildate方法 验证算式字符串是否合法
public static bool Vaildate(string input)
{
bool flag = true;
string ErrorMsg = string.Empty;
//判断算式去除字母和空字符后是否为空
if (input.Length == 0)
{
flag = false;
ErrorMsg = "Empty string";
goto Tail;
}
//判断算式是否含有非法字符
if (new Regex("[^0-9.*+/()#-]").IsMatch(input))
{
flag = false;
ErrorMsg = "Illegal character exists";
goto Tail;
}
//判断算式末尾是否含有#号
if (!input.EndsWith("#"))
{
flag = false;
ErrorMsg = "Miss a hashtag";
goto Tail;
}
//判断括号是否配对
Stack Brackets = new Stack();
if (input.Contains(")(") || input.Contains("()"))
{
flag = false;
ErrorMsg = "Brackets not match";
goto Tail;
}
foreach (char c in input)
{
if (c == '(')
{
Brackets.Push(c.ToString());
}
else if (c == ')')
{
if (Brackets.IsEmpty())
{
flag = false;
ErrorMsg = "Brackets not match";
goto Tail;
}
else
{
Brackets.Pop();
}
}
}
if (!Brackets.IsEmpty())
{
flag = false;
ErrorMsg = "Brackets not match";
goto Tail;
}
//判断算是是否符合语法
if (new Regex("^[.*+/-]").IsMatch(input) || new Regex("[.*+/-](?=#?$)").IsMatch(input) || new Regex("[*+/#()-]+[.]").IsMatch(input) || new Regex("[.][*+/#()-]+").IsMatch(input) || new Regex("[0-9]+[.][0-9]+[.][0-9]+").IsMatch(input) || new Regex("[.*+/#-]{2,}").IsMatch(input) || new Regex("[#].*[#]").IsMatch(input))
{
flag = false;
ErrorMsg = "Syntax error";
goto Tail;
}
Tail:
if (!flag)
{
Console.WriteLine(ErrorMsg);
}
return(flag);
}
public string GetReverseNotation(string line, out Stack <Actions> actions, out Stack <string> operands)
{
string result = "";
actions = new Stack <Actions>();
operands = new Stack <string>();
Stack <Actions> functions = new Stack <Actions>();
for (int i = 0; i < line.Length; i++)
{
if (IsSplite(line[i]))
{
continue;
}
if (IsDigit(line[i]) && (i == 0 || line[i - 1] != '.'))
{
AddDigits(ref result, line, ref i, operands);
continue;
}
if (line[i] == '(')
{
functions.Push(new Actions("(", false, -1));
continue;
}
if (line[i] == ')')
{
AddFunctionsAndOperations(functions, ref result, actions);
continue;
}
if (IsBinaryOperation(line, i))
{
AddOperationToStack(functions, line, i, ref result, actions);
continue;
}
if (IsConstant(line, ref i, ref result, operands))
{
continue;
}
AddFunctionToStack(functions, line, ref i);
}
while (!functions.IsEmpty())
{
if (!IsFunction(functions.Top().Name) && (functions.Top().Name.Length == 0 ||
functions.Top().Name[0] != '+' && functions.Top().Name[0] != '-' &&
functions.Top().Name[0] != '*' && functions.Top().Name[0] != '/' &&
functions.Top().Name[0] != '^'))
{
throw new Exception("Строка не корректно задана");
}
result += functions.Top().Name;
actions.Push(functions.Top());
result += ' ';
functions.Pop();
}
actions = actions.ReverseStack();
operands = operands.ReverseStack();
return(result);
}
private bool IsUnaryOperation(string line, int index, Stack <Actions> functions)
{
return(index == 0 || IsBinaryOperation(line, index - 1) ||
line[index - 1] == '(' ||
!functions.IsEmpty() && functions.Top().IsFunction);
}
// 进行运算
private double Calculate(string operators, string numbers) {
// 将数字和操作符字符串存到数组当中
string[] numberarray = Regex.Split(numbers, " ");
string[] operatorarray = Regex.Split(operators, " ");
Stack numberStack = new Stack();// 数字栈
Stack operatorStack = new Stack();// 操作符栈
// 先将前两个数字和一个操作符push到栈中
numberStack.Push(Convert.ToDouble(numberarray[0]));
numberStack.Push(Convert.ToDouble(numberarray[1]));
operatorStack.Push(operatorarray[0]);
// 当遍历完操作符数组且栈中操作符为空时跳出循环
for (int i = 1; i < operatorarray.Length || !operatorStack.IsEmpty();) {
// 当操作符栈为空时，push一个数字和一个操作符
if (operatorStack.IsEmpty()) {
numberStack.Push(Convert.ToDouble(numberarray[i + 1]));
operatorStack.Push(operatorarray[i]);
i++;continue;
}
// 当栈顶操作符为+或者-时
if (operatorStack.getTop().Equals("+") || operatorStack.getTop().Equals("-")) {
if (i < operatorarray.Length) { // 当下一个操作符不是最后一个操作符时
// 如果下一个操作符为*或者/，则push一个数字和操作符
if (operatorarray[i].Equals("*") || operatorarray[i].Equals("/")) {
numberStack.Push(Convert.ToDouble(numberarray[i + 1]));
operatorStack.Push(operatorarray[i]);
i++;
} else {// 否则，栈内进行加减运算，将结果push到栈顶，下同
double after = Convert.ToDouble(numberStack.Pop());
double pre = Convert.ToDouble(numberStack.Pop());
string op = operatorStack.Pop().ToString();
switch (op) {
case "+": { numberStack.Push(pre + after); continue; }
case "-": { numberStack.Push(pre - after); continue; }
default: continue;
}
}
} else {// 如果没有下一个操作符，则栈内进行加减运算
double after = Convert.ToDouble(numberStack.Pop());
double pre = Convert.ToDouble(numberStack.Pop());
string op = operatorStack.Pop().ToString();
switch (op) {
case "+": { numberStack.Push(pre + after); continue; }
case "-": { numberStack.Push(pre - after); continue; }
default: continue;
}
}
} else {// 如果栈顶操作符为*或者/，则栈内直接进行乘除运算
double after = Convert.ToDouble(numberStack.Pop());
double pre = Convert.ToDouble(numberStack.Pop());
string op = operatorStack.Pop().ToString();
switch (op) {
case "*": { numberStack.Push(pre * after); continue; }
case "/": { numberStack.Push(pre / after); continue; }
default: continue;
}
}
}
// 取出栈顶元素作为结果返回
object result = numberStack.Pop();
return Convert.ToDouble(result);
}
private List <String> infixToPostfix(char[] operand) //中缀表达式转换为后缀表达式
{
List <String> str1 = new List <string>(); //因数及运算符存储
Stack <char> s = new Stack <char>();
char y = '\0'; s.Push('#'); //#号作为结束的标志
for (int i = 0; i < operand.Length; i++)
{
if (operand[i] >= '0' && operand[i] <= '9')
{
double sum = 0, //运算符边的数字
sum1 = 0; //运算符边的数字
int n = 0;
bool dot = false; //判断是否有小数点
bool mod = false; //判断是否有模运算
for (; i < operand.Length && (operand[i] >= '0' && operand[i] <= '9' || operand[i] == '.' || operand[i] == '!' || operand[i] == '%'); i++)
{
if (operand[i] == '.')//判断是否有小数点
{
dot = true;
continue;
}
if (operand[i] == '!') //计算阶乘
{
if (!dot)
{
sum = factorial(sum); //判断，小数没有阶乘
}
else
{
Form1.str = "错误";
}
continue;
}
if (operand[i] == '%') //判断是否有模运算
{
mod = true;
sum1 = sum;
sum = 0;
continue;
}
if (!dot)
{
sum = sum * 10 + (operand[i] - '0'); //算整数
}
else //加上小数
{
sum = sum + (operand[i] - '0') * Math.Pow(10, -++n);
}
if (mod)
{
if ((i + 1) < operand.Length && (operand[i + 1] >= '0' && operand[i + 1] <= '9' || operand[i + 1] == '.' || operand[i + 1] == '!' || operand[i + 1] == '%'))
{
;
}
else if (sum >= 1)
{
sum = (int)sum1 % (int)sum;
}
else
{
Form1.str = "错误";
}
}
}
i--; //把多增加的i减回来
str1.Add(sum.ToString());
}
else if (operand[i] == '√') //求根号
{
double sum = 0;
int n = 0;
bool dot = false;
for (i++; i < operand.Length && (operand[i] >= '0' && operand[i] <= '9' || operand[i] == '.' || operand[i] == '!'); i++)
{
if (operand[i] == '.')//判断是否有小数点
{
dot = true;
continue;
}
if (operand[i] == '!') //计算阶乘
{
if (!dot)
{
sum = factorial(sum); //判断，小数没有阶乘
}
else
{
Form1.str = "错误";
}
continue;
}
if (!dot)
{
sum = sum * 10 + (operand[i] - '0'); //算整数
}
else //加上小数
{
sum = sum + (operand[i] - '0') * Math.Pow(10, -++n);
}
}
sum = Math.Sqrt(sum); //求根号
i--; //把多增加的i减回来
str1.Add(sum.ToString());
}
else if (operand[i] == ')')
{
for (s.Top(ref y), s.Pop(); y != '('; s.Top(ref y), s.Pop())
{
str1.Add(y.ToString());
}
}
else
{
for (s.Top(ref y), s.Pop(); icp(operand[i]) <= isp(y); s.Top(ref y), s.Pop())
{
str1.Add(y.ToString());
}
s.Push(y);
s.Push(operand[i]);
}
}
while (!s.IsEmpty())
{
s.Top(ref y);
s.Pop();
if (y != '#')
{
str1.Add(y.ToString());
}
}
return(str1);
}