java做一个中缀表达式变后缀表达式的函数的问题

我有个计算器程序，是先把中缀转后缀的。

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import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JTextField;

class Stack_Float

{

float nums[];

int top;

Stack_Float()

{

nums = new float[50];

top = -1;

}

boolean IsEmpty()

{

if (top == -1)

return true;

else

return false;

}

float Pop_Stack()

{

if (top == -1)

{

return 0;

}

top--;

return nums[top + 1];

}

float GetTop()

{

return nums[top];

}

void Push_Stack(float num)

{

if (top == 49)

return;

top++;

nums[top] = num;

}

}

class Stack_Char

{

char str[];

int top;

Stack_Char()

{

str = new char[50];

top = -1;

}

boolean CanPush(char c)

{

int temp = top;

if (c == '(')

{

while (temp != -1)

{

if (str[temp] == '(')

{

return false;

}

temp--;

}

}

temp = top;

if (c == '[')

{

while (temp != -1)

{

if (str[temp] == '[' || str[temp] == '(')

{

return false;

}

temp--;

}

}

if (c == '{')

{

while (temp != -1)

{

if (str[temp] == '{' || str[temp] == '[' || str[temp] == '(')

{

return false;

}

temp--;

}

}

return true;

}

boolean IsEmpty()

{

if (top == -1)

return true;

else

return false;

}

void Push_Stack(char ch)

{

if (top == 49)

return;

top++;

str[top] = ch;

}

char Pop_Stack()

{

if (top == -1)

return '\0';

top--;

return str[top + 1];

}

char GetTop()

{

if (top == -1)

{

System.out.print("error");

System.exit(0);

}

return str[top];

}

}

public class jisuanqi extends javax.swing.JFrame implements ActionListener

{

JTextField text = new JTextField();

JTextField text1 = new JTextField();

JButton jButton1 = new JButton();

JButton jButton2 = new JButton();

JButton jButton3 = new JButton();

JButton jButton4 = new JButton();

JButton jButton5 = new JButton();

JButton jButton6 = new JButton();

JButton jButton7 = new JButton();

JButton jButton8 = new JButton();

JButton jButton9 = new JButton();

JButton jButton10 = new JButton();

JButton jButton11 = new JButton();

JButton jButton12 = new JButton();

JButton jButton13 = new JButton();

JButton jButton14 = new JButton();

JButton jButton15 = new JButton();

JButton jButton16 = new JButton();

JButton jButton17 = new JButton();

JButton jButton18 = new JButton();

JButton jButton19 = new JButton();

JButton jButton20 = new JButton();

JButton jButton21 = new JButton();

JButton jButton22 = new JButton();

String show = "";

public jisuanqi()

{

initComponents();

}

char[] TranSmit(char str[])

{

char houzhui[] = new char[50]; // 存放后缀表达式的字符串

int i = 0, j = 0;

char c = str[i];

Stack_Char s = new Stack_Char(); // 存放运算符的栈

while (c != '=') // 对算术表达式扫描未结束时

{

if (c = '0' c = '9')

{

while (c = '0' c = '9')// 数字直接入栈

{

houzhui[j] = c;

j++;

i++;

c = str[i];

}

houzhui[j] = '#';// 用#隔开数字

j++;

}

switch (c) // 扫描到运算符时

{

case '+':

case '-':

case '*':

case '/':

case '(':

case '[':

case '{':

if (s.IsEmpty() == true) // 栈空,直接入栈

{

s.Push_Stack(c);

i++;

c = str[i];

break;

}

if (ComPare(s.GetTop(), c) == -1) {

s.Push_Stack(c); // 入栈

i++;

c = str[i];

break;

}

if (ComPare(s.GetTop(), c) == 1) {

houzhui[j] = s.Pop_Stack();// 出栈元素存入后缀表达式

j++;

break;

}

case ')': // 扫描到 )

while (s.GetTop() != '(') // 未扫描到 ( 时,出栈

{

houzhui[j] = s.Pop_Stack();

j++;

}

s.Pop_Stack(); // '(' 出栈

i++;

c = str[i];

break;

case ']': // 扫描到 ]

while (s.GetTop() != '[') // 未扫描到 [ 时,出栈

{

houzhui[j] = s.Pop_Stack();

j++;

}

s.Pop_Stack(); // '[' 出栈

i++;

c = str[i];

break;

case '}': // 扫描到 }

while (s.GetTop() != '{') // 未扫描到 { 时,出栈

{

houzhui[j] = s.Pop_Stack();

j++;

}

s.Pop_Stack(); // '{' 出栈

i++;

c = str[i];

break;

}

}

while (s.IsEmpty() != true)// 把剩余的运算符直接出栈

{

houzhui[j] = s.Pop_Stack();

j++;

}

houzhui[j] = '=';// 后缀表达式后面加 =

j++;

houzhui[j] = '\0';

j++;

return houzhui;

}

float Count(char str[])

{

Stack_Float s = new Stack_Float();// 定义存放数字的栈

char c = str[0];

int i = 0;

float result = 0, temp, left, right;

while (c != '=') // 未扫描到 = 时

{

if (c = '0' c = '9')// 扫描到数字

{

temp = 0;

while (c != '#')// 未读到分隔符时

{

temp = temp * 10 + c - '0';

i++;

c = str[i];

}

s.Push_Stack(temp);// 进栈

}

switch (c)// 扫描到运算符时

{

case '+':

{

result = s.Pop_Stack() + s.Pop_Stack();// 2个数字出栈相加

s.Push_Stack(result);// 最后得数进栈

break;

}

case '-':

{

right = s.Pop_Stack();// 右操作数出栈

left = s.Pop_Stack();// 左操作数出栈

result = left - right;

s.Push_Stack(result);

break;

}

case '*':

{

result = s.Pop_Stack() * s.Pop_Stack();// 2个数字出栈相乘

s.Push_Stack(result);

break;

}

case '/':

{

right = s.Pop_Stack();// 右操作数出栈

left = s.Pop_Stack();// 左操作数出栈

result = left / right;

s.Push_Stack(result);

break;

}

}

i++;

c = str[i];

}

return result;

}

int ComPare(char a, char b) // 判断运算符的优先级函数

{

int s[][] = {// 栈顶元素高于算术表达式中的元素时, 返回 1,否则返回 -1

{ 1, 1, -1, -1, -1, 1, -1, 1, -1, 1 },

{ 1, 1, -1, -1, -1, 1, -1, 1, -1, 1 },

{ 1, 1, 1, 1, -1, 1, -1, 1, -1, 1 },

{ 1, 1, 1, 1, -1, 1, -1, 1, -1, 1 },

{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

{ 1, 1, 1, 1, -1, 1, -1, -1, -1, -1 },

{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

{ 1, 1, 1, 1, -1, -1, -1, -1, -1, 1 },

{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },

{ 1, 1, 1, 1, -1, -1, -1, -1, -1, -1 } };

char x1[] = { '+', '-', '*', '/', '(', ')', '[', ']', '{', '}' };// 栈顶元素

char x2[] = { '+', '-', '*', '/', '(', ')', '[', ']', '{', '}' };// 算术表达式中的元素

int k = 0, m, n = 0;

for (m = 0; m 10; m++) // 查找2个进行比较的运算符在表中的位置,并返回比较结果

{

for (n = 0; n 10; n++)

{

if (x1[m] == a x2[n] == b)

{

k = 1;

break; // 找到比较结果后,跳出循环

}

}

if (k == 1)

break;

}

return s[m][n];// 返回比较结果

}

public void actionPerformed(ActionEvent e)

{

if (e.getSource() == jButton1)

{

show += "1";

text.setText(show);

}

if (e.getSource() == jButton2)

{

show += "2";

text.setText(show);

}

if (e.getSource() == jButton3)

{

show += "3";

text.setText(show);

}

if (e.getSource() == jButton4)

{

show += "4";

text.setText(show);

}

if (e.getSource() == jButton5)

{

show += "5";

text.setText(show);

}

if (e.getSource() == jButton6)

{

show += "6";

text.setText(show);

}

if (e.getSource() == jButton7)

{

show += "7";

text.setText(show);

}

if (e.getSource() == jButton8)

{

show += "8";

text.setText(show);

}

if (e.getSource() == jButton9)

{

show += "9";

text.setText(show);

}

if (e.getSource() == jButton10)

{

show += "0";

text.setText(show);

}

if (e.getSource() == jButton11)

{

show += "+";

text.setText(show);

}

if (e.getSource() == jButton12)

{

show += "-";

text.setText(show);

}

if (e.getSource() == jButton13)

{

show += "*";

text.setText(show);

}

if (e.getSource() == jButton14)

{

show += "/";

text.setText(show);

}

if (e.getSource() == jButton15)

{

show += "(";

text.setText(show);

}

if (e.getSource() == jButton16)

{

show += ")";

text.setText(show);

}

if (e.getSource() == jButton17)

{

show += "[";

text.setText(show);

}

if (e.getSource() == jButton18)

{

show += "]";

text.setText(show);

}

if (e.getSource() == jButton19)

{

show += "{";

text.setText(show);

}

if (e.getSource() == jButton20)

{

show += "}";

text.setText(show);

}

if (e.getSource() == jButton21)

{

show = "";

text.setText("");

text1.setText("");

}

if (e.getSource() == jButton22)

{

show += "=";

text.setText(show);

char str1[] = new char[50];

char str2[] = new char[50];

float result = 0;

str1 = show.toCharArray();

str2 = TranSmit(str1);

result = Count(str2);

text1.setText((new String(str2)).trim());

text.setText("" + result);

show = "";

}

}

private void initComponents()

{

text.setBounds(10, 10, 270, 30);

text1.setBounds(10, 50, 270, 30);

jButton1.setBounds(10, 90, 60, 25);

jButton2.setBounds(80, 90, 60, 25);

jButton3.setBounds(150, 90, 60, 25);

jButton4.setBounds(220, 90, 60, 25);

jButton5.setBounds(10, 120, 60, 25);

jButton6.setBounds(80, 120, 60, 25);

jButton7.setBounds(150, 120, 60, 25);

jButton8.setBounds(220, 120, 60, 25);

jButton9.setBounds(10, 150, 60, 25);

jButton10.setBounds(80, 150, 60, 25);

jButton11.setBounds(150, 150, 60, 25);

jButton12.setBounds(220, 150, 60, 25);

jButton13.setBounds(10, 180, 60, 25);

jButton14.setBounds(80, 180, 60, 25);

jButton15.setBounds(150, 180, 60, 25);

jButton16.setBounds(220, 180, 60, 25);

jButton17.setBounds(150, 210, 60, 25);

jButton18.setBounds(220, 210, 60, 25);

jButton19.setBounds(10, 210, 60, 25);

jButton20.setBounds(80, 210, 60, 25);

jButton21.setBounds(10, 240, 60, 25);

jButton22.setBounds(80, 240, 60, 25);

jButton1.setText("1");

jButton2.setText("2");

jButton3.setText("3");

jButton4.setText("4");

jButton5.setText("5");

jButton6.setText("6");

jButton7.setText("7");

jButton8.setText("8");

jButton9.setText("9");

jButton10.setText("0");

jButton11.setText("+");

jButton12.setText("-");

jButton13.setText("*");

jButton14.setText("/");

jButton15.setText("(");

jButton16.setText(")");

jButton17.setText("[");

jButton18.setText("]");

jButton19.setText("{");

jButton20.setText("}");

jButton21.setText("CE");

jButton22.setText("=");

jButton1.addActionListener(this);

jButton2.addActionListener(this);

jButton3.addActionListener(this);

jButton4.addActionListener(this);

jButton5.addActionListener(this);

jButton6.addActionListener(this);

jButton7.addActionListener(this);

jButton8.addActionListener(this);

jButton9.addActionListener(this);

jButton10.addActionListener(this);

jButton11.addActionListener(this);

jButton12.addActionListener(this);

jButton13.addActionListener(this);

jButton14.addActionListener(this);

jButton15.addActionListener(this);

jButton16.addActionListener(this);

jButton17.addActionListener(this);

jButton18.addActionListener(this);

jButton19.addActionListener(this);

jButton20.addActionListener(this);

jButton21.addActionListener(this);

jButton22.addActionListener(this);

add(text);

add(text1);

add(jButton1);

add(jButton2);

add(jButton3);

add(jButton4);

add(jButton5);

add(jButton6);

add(jButton7);

add(jButton8);

add(jButton9);

add(jButton10);

add(jButton11);

add(jButton12);

add(jButton13);

add(jButton14);

add(jButton15);

add(jButton16);

add(jButton17);

add(jButton18);

add(jButton19);

add(jButton20);

add(jButton21);

add(jButton22);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setLayout(null);

setBounds(300, 300, 300, 300);

setVisible(true);

}

public static void main(String args[])

{

new jisuanqi();

}

}

求后缀转换中缀的方法,不是中缀转换后缀

可通过加括号的方法来进行，下面举例讲解：

1.++a*bc*+*defg前缀转中缀

2.abc*+de*f+g*+后缀转中缀

解：

1.从右向左加括号

首先是++a*bc*+(*de)fg == ++a*bc*(+(*de)f)g……最后到(+(+a(*bc))(*(+(*de)f)g))

可以看出每个括号都是简单的二元式，将括号内前缀转中缀，展开，得

a+b*c+(d*e+f)*g

2.从左向右加括号

首先是a(bc*)+de*f+g*+ == (a(bc*)+)de*f+g*+……最后到((a(bc*)+)(((de*)f+)g*)+)

同样的，可以看出每个括号都是简单的二元式，将括号内后缀转中缀，展开，得

a+b*c+(d*e+f)*g

java中缀转后缀

首先inOrderList的类型是ArrayListString。ArrayListString就是一个可变长数组，数组里的每个元素是一个字符串。

其次，第二个问题问的不是很明确。[所有集合的方法]指的是什么？ArrayList只是一种集合，常用的还有map等。后面的是泛型，jdk1.5以后才支持的，便于类型的指定，在编译的级别可以杜绝一部分类型转换的错误。补充一下，但泛型不能根本上解决集合元素，类型转换的所有问题。

java中缀表达式转后缀表达式求值

public MyStack(int maxSize){//构造方法的重载 建立指定的栈的大小

top=-1;//因为栈操作在操作顶层 先进后出 指针初始为-1

arr=(T[])new Object[maxSize];

}

public void push(T value){

arr[++top]=value;

}//入栈操作 指针下移动

public T pop(){return arr[top--];//top指针上移动 及就是pop推出元素并且删除

}

public T peek(){

return arr[top];

}//查询某个元素

public boolean isEmpty(){

return top==-1;

}//判断栈是否为空 判断top指针是否改变就可

public boolean isFool(){

后缀式转中缀式

这道题还是有难度，连悬赏分都没有。C语言作业要自己写，才能锻炼自己的能力。

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