一、應(yīng)用介紹

安卓計(jì)算器：
實(shí)現(xiàn)功能：
（1）能實(shí)現(xiàn)基本的加減乘除運(yùn)算、回退和清空輸入。
（2）豎屏?xí)r能實(shí)現(xiàn)基本的加減乘除運(yùn)算、回退和清空輸入。橫屏?xí)r變?yōu)榭茖W(xué)計(jì)算器，實(shí)現(xiàn)函數(shù)計(jì)算、進(jìn)制換算等功能。
（3）數(shù)字按鍵依照電話撥號(hào)鍵盤順序排列。
（4）點(diǎn)擊菜單可對(duì)計(jì)算器相關(guān)特性進(jìn)行配置。
（5）輸入計(jì)算公式，按等號(hào)鍵輸出計(jì)算結(jié)果。
（6）公式輸入和結(jié)果顯示區(qū)應(yīng)支持長(zhǎng)按彈出復(fù)制、粘貼功能。
（7）使用計(jì)算器過(guò)程中應(yīng)不彈出軟鍵盤。
（8）可以通過(guò)進(jìn)度條實(shí)時(shí)調(diào)整計(jì)算結(jié)果保留的小數(shù)點(diǎn)后位數(shù)，或者通過(guò)音量鍵完成同樣的效果。
（9）實(shí)現(xiàn)附加功能：三角函數(shù)、階乘、XY、√(Y&X)及括號(hào)，如sin(90)。
（10）輸入表達(dá)式按優(yōu)先級(jí)計(jì)算，按等號(hào)輸出結(jié)果。
（11）對(duì)常用鍵布局需考慮特殊處理。
（12）處理精度和容錯(cuò)問(wèn)題：
a.1/3+1/3+1/3；
2.1+0.001；
1.1-1.001；
1/0、1/(1-1)和1/sin(0)等;
3/2;
對(duì)有附加功能的需要處理特殊值，如：√(2&-1) 等。

二、 運(yùn)行截圖

豎屏?xí)r

橫屏?xí)r

主要代碼
MainActivity.java

public class MainActivity extends AppCompatActivity {String formula = "";//公式方程Boolean zeroMark = true; //允許輸入一個(gè)0Boolean zeroCon = false;//允許持續(xù)輸入0Boolean docMark = true;// . 可以輸入 .Boolean resultMark = false; //結(jié)果是否計(jì)算出Boolean transformMark = false; //是否進(jìn)行二進(jìn)制轉(zhuǎn)化Boolean errorMark = false;Boolean numAndOpMark = true;int color = 0xffffffff;private static final String REGEX = "^\\d+$";//all is numint precision = 3; //保留小數(shù)點(diǎn)位數(shù)@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR); //屏幕旋轉(zhuǎn)setContentView(R.layout.col);EditText show = findViewById(R.id.show);show.setText("");show.setSelectAllOnFocus(true); // 設(shè)置長(zhǎng)按時(shí)選擇全部calculator();}public void calculator() {disableShowInput(); // 不讓彈出軟鍵盤EditText show = findViewById(R.id.show);Button dot = findViewById(R.id.dot);Button zero = findViewById(R.id.zero);Button one = findViewById(R.id.one);Button two = findViewById(R.id.two);Button three = findViewById(R.id.three);Button four = findViewById(R.id.four);Button five = findViewById(R.id.five);Button six = findViewById(R.id.six);Button seven = findViewById(R.id.seven);Button eight = findViewById(R.id.eight);Button nine = findViewById(R.id.nine);Button add = findViewById(R.id.add);Button sub = findViewById(R.id.sub);Button division = findViewById(R.id.division);Button back = findViewById(R.id.back);Button AC = findViewById(R.id.AC);Button mul = findViewById(R.id.mul);Button eval = findViewById(R.id.eval);Button percent = findViewById(R.id.percent);Button sin = findViewById(R.id.sin);Button power = findViewById(R.id.power);Button factorial = findViewById(R.id.factorial); //階乘Button square = findViewById(R.id.square); //開(kāi)根號(hào)Button brackets = findViewById(R.id.brackets);Button transform = findViewById(R.id.transform);dot.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum(".");}});zero.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("0");}});one.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("1");}});two.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("2");}});three.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("3");}});four.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("4");}});five.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("5");}});six.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("6");}});seven.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("7");}});eight.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("8");}});nine.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("9");}});add.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("+");}});sub.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("-");}});mul.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("×");}});division.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("÷");}});AC.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {reSetStatus();show.setText("");}});back.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (formula.length() > 0) {if (!formula.contains("(D->B)")) {if (lastStr().equals(".")) {docMark = true;}formula = formula.substring(0, formula.length() - 1);} else {formula = formula.replace("(D->B)", "");numAndOpMark = true;transformMark = false;}show.setText(formula);show.setTextColor(0xff000000);}}});eval.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {try {String result = "";if (transformMark) { // 先判斷是不是要進(jìn)行二進(jìn)制轉(zhuǎn)化doTransform();return;}delLastOp(); // 如果式子是 4- 進(jìn)行計(jì)算,我們打算將-號(hào)去掉,結(jié)果為4try {result = Result.getRes(formula) + ""; //將計(jì)算式放入getRes函數(shù)中進(jìn)行計(jì)算} catch (Exception e) {show.setText(e.getMessage()); //getRes中拋出的異常進(jìn)行抓取并顯示show.setTextColor(0xffff0000);errorMark = true;return;}System.out.println(result + "result");if (result.contains("E") && !result.contains("E-")) {// 結(jié)果使用了科學(xué)計(jì)數(shù)法表示,我們要根據(jù)情況進(jìn)行處理show.setText(result);Toast toast = Toast.makeText(getApplicationContext(), "數(shù)值太大,已用科學(xué)計(jì)數(shù)法表示", Toast.LENGTH_SHORT);toast.show();return;} // String intPart;// if (result.length() > 12) {if (result.contains("E-")) {BigDecimal decimal = new BigDecimal(result);result = decimal.toPlainString();}if (result.length() > 12){result = result.substring(0, 11);}result = doPrecision(result); //進(jìn)行精讀修改show.setText(result);reSetStatus();formula = result;resultMark = true;docMark = true;} catch (Exception e) {e.printStackTrace();}}});percent.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (formula.length() > 0) {if (!numAndOpMark) {return;}formula = "(" + formula + ")*0.01";try {show.setText(doEval(formula));formula = doEval(formula);} catch (Exception e) {show.setText(e.getMessage());}}}});sin.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}formula = formula + "sin(";show.setText(formula);}});square.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}formula = formula + "v(";show.setText(formula);}});power.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}formula = formula + "^";show.setText(formula);}});factorial.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}try {if (formula.contains(".") ){Toast toast = Toast.makeText(getApplicationContext(), "小數(shù)不可以階乘", Toast.LENGTH_SHORT);toast.show();return;}if (Result.getRes(formula) < 171) {formula = formula + "!";show.setText(formula);} else {Toast toast = Toast.makeText(getApplicationContext(), "數(shù)值太大!", Toast.LENGTH_SHORT);toast.show();show.setTextColor(0xffff0000);resultMark = true;}} catch (Exception e) {e.printStackTrace();}}});brackets.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}if (lastIsNum() || lastStr().equals(")")) {formula = formula + ")";} else {formula = formula + "(";}show.setText(formula);}});transform.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (formula.matches(REGEX)) {formula = formula + "(D->B)";show.setText(formula);transformMark = true;numAndOpMark = false;}}});}public String doPrecision(String result) {System.out.println(result + "rep");String tail = result.split("\\.")[1];String pre = result.split("\\.")[0];int deltaPre = precision - tail.length();if (deltaPre > 0) {for (int i = 0; i < deltaPre; i++) {result = result + "0";}} else if (deltaPre < 0) {double doubleResult = Double.parseDouble(result);BigDecimal bigResult = new BigDecimal(doubleResult);result = bigResult.setScale(precision, BigDecimal.ROUND_HALF_UP).toString();}System.out.println(result + "pre");return result;}public void reSetStatus() { //將各個(gè)監(jiān)控狀態(tài)設(shè)為初始狀態(tài)EditText show = findViewById(R.id.show);show.setTextColor(0xff000000);formula = "";zeroMark = true;zeroCon = false;docMark = true;resultMark = false;transformMark = false;numAndOpMark = true;}@SuppressLint("SetTextI18n")public void doTransform() { //二進(jìn)制轉(zhuǎn)化方法EditText show = findViewById(R.id.show);transformMark = false;String num = formula.split("\\(")[0];show.setText(Integer.toBinaryString(Integer.parseInt(num)) + "B");resultMark = true;docMark = true;}public String lastStr() {if (formula.length() > 0) {return formula.charAt(formula.length() - 1) + "";} else {return "";}} //返回字符的最后一個(gè)字符public String doEval(String formula) throws Exception { //做簡(jiǎn)單的計(jì)算方法ScriptEngineManager manager = new ScriptEngineManager();ScriptEngine se = manager.getEngineByName("js");return se.eval(formula) + "";}public Boolean lastIsNum() { //最后一位是不是數(shù)字if (formula.length() == 0) {return false;} else {char lastChar = formula.charAt(formula.length() - 1);return lastChar > 47 && lastChar < 58;}}public Boolean lastIsOp() { //最后一位字符是不是操作符return isOp(lastStr());}public Boolean isOp(String str) { //傳遞的參數(shù)是不是操作符return (str.equals("+") || str.equals("×")|| str.equals("÷") || str.equals("-"));}public void doNum(String num) {EditText show = findViewById(R.id.show);show.setTextColor(0xff000000);int length = formula.length();if (!numAndOpMark) { //當(dāng)使用(D->B)后我們不再允許進(jìn)行任何符號(hào)的輸入return;}if (errorMark) { //是否出錯(cuò)reSetStatus();errorMark = false;}if (resultMark) { //結(jié)果是否已算出formula = "";resultMark = false;}if (num.equals(".")) { //輸?shù)淖址遣皇屈c(diǎn) .000000000000if (docMark) { // && !isOp(lastStr())formula = formula + '.';show.setText(formula);docMark = false;zeroCon = true;}return;}if (num.equals("0")) { //是不是0? 00000000000if (zeroCon || zeroMark) {formula = formula + '0';}show.setText(formula);zeroMark = false;return;}if (formula.startsWith("0") && length == 1) { //0的特殊情況 09 -> 9formula = "";}if (length > 2 && formula.endsWith("0") && isOp(formula.charAt(length - 2) + "")) {formula = formula.substring(0, length - 1); // 0的特殊情況 23 + 09 -> 23 + 9}formula = formula + num; //加入計(jì)算式zeroCon = true;show.setText(formula);}public void doOp(String op) {EditText show = findViewById(R.id.show);show.setTextColor(0xff000000);if (!numAndOpMark || lastStr().equals(".")) {return;}if (errorMark) { //是否有錯(cuò)誤 - is okreSetStatus();errorMark = false;}if (resultMark) { //結(jié)果是否計(jì)算出formula = show.getText().toString();resultMark = false;}if ((lastStr().equals("÷") || lastStr().equals("×")) && op.equals("-")) {addOp(op);return;}if (formula.contains("×-") || formula.contains("÷-")) {formula = formula.substring(0, formula.length() - 2);}if (formula.length() == 1 && lastStr().equals("-")) { // 只有一個(gè)減號(hào),不允許輸任何操作符return;}if (formula.length() == 0 || lastStr().equals("(")) { //1+(?=-if (op.equals("-")) { // 第一個(gè)輸入的字符是不是-addOp(op);}return;}if (lastIsOp() && formula.length() > 0) { //若最后一個(gè)字符已經(jīng)時(shí)操作符,那要替換掉舊的替換符formula = formula.substring(0, formula.length() - 1);}addOp(op); //如果沒(méi)有以上特殊情況,則加到計(jì)算式里}public void addOp(String op) { // 輸入操作符時(shí)大部分的重復(fù)工作進(jìn)行封裝EditText show = findViewById(R.id.show);formula = formula + op;docMark = true;zeroMark = true;zeroCon = false;show.setText(formula);}//==================================================================================@SuppressLint("SetTextI18n")@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) { //設(shè)置精度(通過(guò)音量鍵)TextView info = findViewById(R.id.info);switch (keyCode) {case KeyEvent.KEYCODE_VOLUME_DOWN:if (precision > 1) {precision--;info.setText("保留" + precision + "位");Toast.makeText(this, "保留" + precision + "位", Toast.LENGTH_SHORT).show();} else {Toast.makeText(this, "至少保留1位", Toast.LENGTH_SHORT).show();}break;case KeyEvent.KEYCODE_VOLUME_UP:if (precision < 10) {precision++;Toast.makeText(this, "保留" + precision + "位", Toast.LENGTH_SHORT).show();info.setText("保留" + precision + "位");} else {Toast.makeText(this, "至多保留10位", Toast.LENGTH_SHORT).show();}break;}return super.onKeyDown(keyCode, event);}@SuppressLint("SetTextI18n")@Overridepublic void onConfigurationChanged(Configuration newConfig) { //橫豎屏切換時(shí)進(jìn)行設(shè)置@SuppressLint("CutPasteId") EditText show1 = findViewById(R.id.show);color = show1.getCurrentTextColor();formula = show1.getText().toString(); //如果你是復(fù)制進(jìn)去的式子,那必須先從show中得到式子// TODO Auto-generated method stubsuper.onConfigurationChanged(newConfig);//啟動(dòng)時(shí)默認(rèn)是豎屏if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {setContentView(R.layout.col);@SuppressLint("CutPasteId") EditText show = findViewById(R.id.show);show.setText(formula);show.setTextColor(color);calculator();}//切換就是橫屏else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {setContentView(R.layout.row);@SuppressLint("CutPasteId") EditText show = findViewById(R.id.show);TextView info = findViewById(R.id.info);info.setText("保留" + precision + "位");show.setText(formula);show.setTextColor(color);calculator();}}//========================================================================================@Overridepublic boolean onCreateOptionsMenu(Menu menu) { //生成菜單項(xiàng)MenuInflater inflater = new MenuInflater(this);inflater.inflate(R.menu.menu, menu);return super.onCreateOptionsMenu(menu);}@SuppressLint("NonConstantResourceId")@Override //菜單項(xiàng)無(wú)所謂public boolean onOptionsItemSelected(MenuItem item) {EditText show = findViewById(R.id.show);//先判斷點(diǎn)擊的是哪個(gè)idswitch (item.getItemId()) {case R.id.font_10:show.setTextSize(10 * 2);break;case R.id.font_12:show.setTextSize(12 * 2);break;case R.id.font_14:show.setTextSize(14 * 2);break;case R.id.font_16:show.setTextSize(16 * 2);break;case R.id.font_18:show.setTextSize(18 * 2);break;case R.id.blue:show.setTextColor(Color.BLUE);break;case R.id.red:show.setTextColor(Color.RED);break;case R.id.green:show.setTextColor(Color.GREEN);break;}return super.onOptionsItemSelected(item);}//======================================================================================public void disableShowInput() { //設(shè)置鍵盤不可見(jiàn)EditText show = findViewById(R.id.show);Class<EditText> cls = EditText.class;Method method;try {method = cls.getMethod("setShowSoftInputOnFocus", boolean.class);method.setAccessible(true);method.invoke(show, false);} catch (Exception e) {//TODO: handle exception}try {method = cls.getMethod("setSoftInputShownOnFocus", boolean.class);method.setAccessible(true);method.invoke(show, false);} catch (Exception e) {//TODO: handle exception}}//=============================================================================public void delLastOp() { //寫個(gè)小遞歸,后來(lái)想想好像用不到,但懶得改了if (isOp(formula.charAt(formula.length() - 1) + "") || lastStr().equals(".")) {formula = formula.substring(0, formula.length() - 1);delLastOp();}}

ArrayStack.java

class ArrayStack {private int maxSize; // 棧的大小private double[] stack; // 數(shù)組，數(shù)組模擬棧，數(shù)據(jù)就放在該數(shù)組private int top = -1;// top表示棧頂，初始化為-1//構(gòu)造器public ArrayStack(int maxSize) {this.maxSize = maxSize;stack = new double[this.maxSize];}//增加一個(gè)方法，可以返回當(dāng)前棧頂?shù)闹? 但是不是真正的poppublic double peek() {return stack[top];}//棧滿public boolean isFull() {return top == maxSize - 1;}//棧空public boolean isEmpty() {return top == -1;}//入棧-pushpublic void push(double value) {//先判斷棧是否滿if (isFull()) {System.out.println("表達(dá)式錯(cuò)誤");return;}top++;stack[top] = value;}//出棧-pop, 將棧頂?shù)臄?shù)據(jù)返回public double pop() {//先判斷棧是否空if (isEmpty()) {//拋出異常throw new RuntimeException("表達(dá)式錯(cuò)誤");}double value = stack[top];top--;return value;}//顯示棧的情況[遍歷棧]， 遍歷時(shí)，需要從棧頂開(kāi)始顯示數(shù)據(jù)public void list() {if (isEmpty()) {System.out.println("表達(dá)式錯(cuò)誤");return;}//需要從棧頂開(kāi)始顯示數(shù)據(jù)for (int i = top; i >= 0; i--) {System.out.printf("stack[%d]=%d\n", i, stack[i]);}}//返回運(yùn)算符的優(yōu)先級(jí)，優(yōu)先級(jí)是程序員來(lái)確定, 優(yōu)先級(jí)使用數(shù)字表示//數(shù)字越大，則優(yōu)先級(jí)就越高.public int priority(int oper) {if (oper == '*' || oper == '/') {return 1;} else if (oper == '+' || oper == '-') {return 0;} else if (oper == '^'||oper == '#') {return 2;} else if (oper == '!' || oper == 'v' || oper == '%') {return 3;} else if (oper == 's' || oper == 't' || oper == 'c') {return 4;} else {return -1; // 假定目前的表達(dá)式只有 +, - , * , /}}//判斷是不是一個(gè)運(yùn)算符public boolean isNum(char val) {return '0' <= val && val <= '9';}//判斷是不是一個(gè)運(yùn)算符public boolean isOper(char val) {return val == '+' || val == '-' || val == '*' || val == '/' || val == '#' || val == '^' || val == '%' || val == 's' || val == 'c' || val == 't' || val == '!' || val == 'v';}//判斷是不是 (public boolean isLeftBrackets(char val) {return val == '(';}//判斷是不是 )public boolean isRightBrackets(char val) {return val == ')';}//判斷是不是 .public boolean isPoint(char val) {return val == '.';}//判斷是不是 (public boolean isTrigonometric(char val) {return val == 's';}//計(jì)算方法public double cal(double num1, double num2, int oper) {double res = 0; // res 用于存放計(jì)算的結(jié)果switch (oper) {case '+':res = num1 + num2;break;case '-':res = sub(num2,num1);// 注意順序break;case '*':res = num1 * num2;break;case '/':if (num1 == 0) {throw new RuntimeException("定義域錯(cuò)誤");}res = num2 / num1;break;case '^':res = Math.pow(num2, num1);break;default:break;}return res;}/*** 三角函數(shù)運(yùn)算、階乘運(yùn)算或者是開(kāi)根操作** @param num1* @param oper* @return*/public double mixedOperation(double num1, int oper) {double res = 1; // res 用于存放計(jì)算的結(jié)果switch (oper) {case 's':res = Math.sin(num1 * Math.PI / 180);break;case 'c':res = Math.cos(num1 * Math.PI / 180);break;case 't':res = Math.tan(num1 * Math.PI / 180);break;case '!':for (int i = 1; i <= num1; i++) {res *= i;}break;case 'v':if (num1 < 0) {throw new RuntimeException("定義域錯(cuò)誤");}res = Math.sqrt(num1);break;case '%':res = num1 / 100;break;case '#':res = -num1;break;default:break;}return res;}double sub(double x, double y) {BigDecimal initResult = new BigDecimal(x - y); //計(jì)算初步結(jié)果String temp = initResult.toString();if (temp.contains(".")){temp = temp + "00000000000000000000";}else {temp = temp + ".00000000000000000000";}int lengthOfInt = getLengthOfInt(x, y); //結(jié)果整形位數(shù)int lengthOfDec = Math.max(getLengthOfDecimal(x), getLengthOfDecimal(y));int count = lengthOfInt + lengthOfDec + 2; //最后輸出的位數(shù) = 整形位數(shù)+小數(shù)位數(shù)+小數(shù)點(diǎn)位數(shù)+1(四舍五入舍去)double tempResult = Double.parseDouble(temp.substring(0, count)); //將String轉(zhuǎn)換成double,并截取多一位用于四舍五入double power = Math.pow(10, lengthOfDec); //求10的幾次方用來(lái)四舍五入double finalResult = (double) (Math.round(tempResult * power)) / power; //四舍五入Log.i("result", x + "-" + y + "=" + finalResult);//此處的長(zhǎng)度取決于小數(shù)點(diǎn)后面位數(shù)大的return finalResult;}int getLengthOfInt(double x, double y) {int lengthOfInt;int intX = (int) x; //x的整數(shù)部分int intY = (int) y; //y的整數(shù)部分lengthOfInt = String.valueOf(intX - intY).length(); //結(jié)果整形部分的位數(shù) = 相減后整形的位數(shù)return lengthOfInt;}int getLengthOfDecimal(double x) {return String.valueOf(x).split("\\.")[1].length(); //計(jì)算x小數(shù)點(diǎn)后面的位數(shù)} public class Result {public static double getRes(String expression) {System.out.println(expression.length());expression = expression.replace("sin", "s");expression = expression.replace("÷", "/");expression = expression.replace("×", "*");ArrayStack stack=new ArrayStack(20);String exp = "";int count = 0;char[] chars = expression.toCharArray();while (count < chars.length) {if (count == 0 && chars[count] == '-') {chars[count] = '#';}if (count >= 1 && chars[count] == '-' && chars[count - 1] == '(') {chars[count] = '#';}if (count >= 1 && chars[count] == '-' && stack.priority(chars[count-1])>stack.priority(chars[count])) {chars[count] = '#';}exp += chars[count];count++;}expression=exp;//創(chuàng)建兩個(gè)棧，數(shù)棧，一個(gè)符號(hào)棧ArrayStack numStack = new ArrayStack(20);ArrayStack operatorStack = new ArrayStack(20);//定義需要的相關(guān)變量int index = 0;//用于掃描double num1 = 0;double num2 = 0;int oper = 0;double res = 0;char ch = ' '; //將每次掃描得到char保存到chString keepNum = ""; //用于拼接 多位數(shù)//開(kāi)始while循環(huán)的掃描expressionwhile (true) {//依次得到expression 的每一個(gè)字符ch = expression.substring(index, index + 1).charAt(0);//判斷ch是什么，然后做相應(yīng)的處理if (operatorStack.isLeftBrackets(ch)) { //如果是左括號(hào)//直接入符號(hào)棧..operatorStack.push(ch);} else if (operatorStack.isRightBrackets(ch)) { //如果是右括號(hào)while (operatorStack.peek() != '(') { //循環(huán)直到能夠到達(dá) '(' 處oper = (int) operatorStack.pop();if (oper == 's' ||oper == '!' ||oper == 'v' ||oper == '#' ||oper == '%') { //如果棧頂為三角函數(shù)、階乘或者是開(kāi)根num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);//把運(yùn)算的結(jié)果如數(shù)棧numStack.push(res);} else {num1 = numStack.pop();num2 = numStack.pop();res = operatorStack.cal(num1, num2, oper);//把運(yùn)算的結(jié)果如數(shù)棧numStack.push(res);}}//然后將當(dāng)前棧頂?shù)牟僮鞣龇?hào)棧----其實(shí)也就是 '(' 出棧operatorStack.pop();} else if (operatorStack.isOper(ch)) { //如果是運(yùn)算符if (operatorStack.isEmpty() || operatorStack.peek() == '(') {//如果符號(hào)棧為空，或者棧頂為'('operatorStack.push(ch);} else if (operatorStack.priority(ch) > operatorStack.priority((int) operatorStack.peek())) {//如果當(dāng)前優(yōu)先級(jí)比棧頂優(yōu)先級(jí)高，直接入符號(hào)棧.operatorStack.push(ch);} else {while (!operatorStack.isEmpty() &&(operatorStack.priority(ch) <= operatorStack.priority((int) operatorStack.peek()))) {oper = (int) operatorStack.pop();if (!operatorStack.isEmpty() && (operatorStack.peek() == '!' ||operatorStack.peek() == 's' ||operatorStack.peek() == 'v' ||operatorStack.peek() == '#' ||operatorStack.peek() == '%')) {num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);numStack.push(res);//入棧} else {if (oper == 's' ||oper == '!' ||oper == 'v' ||oper == '#' ||oper == '%') { //如果棧頂為三角函數(shù)、階乘或者是開(kāi)根num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);//把運(yùn)算的結(jié)果如數(shù)棧numStack.push(res);} else {num1 = numStack.pop();num2 = numStack.pop();res = numStack.cal(num1, num2, oper);//把運(yùn)算的結(jié)果如數(shù)棧numStack.push(res);}}}//然后將當(dāng)前的操作符入符號(hào)棧operatorStack.push(ch);}} else if (operatorStack.isPoint(ch) || operatorStack.isNum(ch)) { //如果是數(shù)或者是小數(shù)點(diǎn)，則直接入數(shù)棧//numStack.push(ch - 48); // "1+3" '1' => 1//1. 當(dāng)處理多位數(shù)時(shí)，不能發(fā)現(xiàn)是一個(gè)數(shù)就立即入棧，因?yàn)榭赡苁嵌辔粩?shù)//2. 在處理數(shù)，需要向expression的表達(dá)式的index 后再看一位,如果是數(shù)就進(jìn)行掃描，如果是符號(hào)才入棧//3. 因此我們需要定義一個(gè)變量 字符串，用于拼接//處理多位數(shù)keepNum += ch;//如果ch已經(jīng)是expression的最后一位，就直接入棧if (index == expression.length() - 1) {numStack.push(Double.parseDouble(keepNum));} else {//判斷下一個(gè)字符是不是數(shù)字，如果是數(shù)字，就繼續(xù)掃描，如果是運(yùn)算符，則入棧//注意是看后一位，不是index++if (operatorStack.isOper(expression.substring(index + 1, index + 2).charAt(0))|| operatorStack.isRightBrackets(expression.substring(index + 1, index + 2).charAt(0))) {//如果后一位是運(yùn)算符，則入棧 keepNum = "1" 或者 "123"numStack.push(Double.parseDouble(keepNum));//最后keepNum必須清空keepNum = "";}}} else if (!operatorStack.isEmpty() && (operatorStack.peek() == 's' ||operatorStack.peek() == '!' ||operatorStack.peek() == 'v' ||operatorStack.peek() == '#' ||operatorStack.peek() == '%')) { //如果棧頂為三角函數(shù)算式、開(kāi)根或者是階乘oper = (int) operatorStack.pop();num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);//把運(yùn)算的結(jié)果入數(shù)棧numStack.push(res);}//讓index + 1, 并判斷是否掃描到expression最后.index++;if (index >= expression.length()) {break;}}//當(dāng)表達(dá)式掃描完畢，就順序的從 數(shù)棧和符號(hào)棧中pop出相應(yīng)的數(shù)和符號(hào)，并運(yùn)行.while (true) {//如果符號(hào)棧為空，則計(jì)算到最后的結(jié)果, 數(shù)棧中只有一個(gè)數(shù)字【結(jié)果】if (operatorStack.isEmpty()) {break;}if (operatorStack.peek() == 's' ||operatorStack.peek() == '!' ||operatorStack.peek() == 'v' ||operatorStack.peek() == '#' ||operatorStack.peek() == '%') { //如果棧頂為三角函數(shù)算式oper = (int) operatorStack.pop();num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);numStack.push(res);//入棧} else {num1 = numStack.pop();num2 = numStack.pop();oper = (int) operatorStack.pop();res = numStack.cal(num1, num2, oper);numStack.push(res);//入棧}}//將數(shù)棧的最后數(shù)，pop出，就是結(jié)果double res2 = numStack.pop();System.out.println(res2+"ll");return res2;}

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