|
|
@@ -0,0 +1,204 @@
|
|
|
+package com.example.StackByArray;
|
|
|
+
|
|
|
+import java.util.ArrayList;
|
|
|
+import java.util.Collections;
|
|
|
+import java.util.List;
|
|
|
+import java.util.Stack;
|
|
|
+import java.util.regex.Pattern;
|
|
|
+
|
|
|
+public class ReversePolishMultiCalc {
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 匹配 + - * / ( ) 运算符
|
|
|
+ */
|
|
|
+ static final String SYMBOL = "\\+|-|\\*|/|\\(|\\)";
|
|
|
+
|
|
|
+ static final String LEFT = "(";
|
|
|
+ static final String RIGHT = ")";
|
|
|
+ static final String ADD = "+";
|
|
|
+ static final String MINUS= "-";
|
|
|
+ static final String TIMES = "*";
|
|
|
+ static final String DIVISION = "/";
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 加減 + -
|
|
|
+ */
|
|
|
+ static final int LEVEL_01 = 1;
|
|
|
+ /**
|
|
|
+ * 乘除 * /
|
|
|
+ */
|
|
|
+ static final int LEVEL_02 = 2;
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 括号
|
|
|
+ */
|
|
|
+ static final int LEVEL_HIGH = Integer.MAX_VALUE;
|
|
|
+
|
|
|
+
|
|
|
+ static Stack<String> stack = new Stack<>();
|
|
|
+ static List<String> data = Collections.synchronizedList(new ArrayList<String>());
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 去除所有空白符
|
|
|
+ * @param s
|
|
|
+ * @return
|
|
|
+ */
|
|
|
+ public static String replaceAllBlank(String s ){
|
|
|
+ // \\s+ 匹配任何空白字符，包括空格、制表符、换页符等等, 等价于[ \f\n\r\t\v]
|
|
|
+ return s.replaceAll("\\s+","");
|
|
|
+ }
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 判断是不是数字 int double long float
|
|
|
+ * @param s
|
|
|
+ * @return
|
|
|
+ */
|
|
|
+ public static boolean isNumber(String s){
|
|
|
+ Pattern pattern = Pattern.compile("^[-\\+]?[.\\d]*$");
|
|
|
+ return pattern.matcher(s).matches();
|
|
|
+ }
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 判断是不是运算符
|
|
|
+ * @param s
|
|
|
+ * @return
|
|
|
+ */
|
|
|
+ public static boolean isSymbol(String s){
|
|
|
+ return s.matches(SYMBOL);
|
|
|
+ }
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 匹配运算等级
|
|
|
+ * @param s
|
|
|
+ * @return
|
|
|
+ */
|
|
|
+ public static int calcLevel(String s){
|
|
|
+ if("+".equals(s) || "-".equals(s)){
|
|
|
+ return LEVEL_01;
|
|
|
+ } else if("*".equals(s) || "/".equals(s)){
|
|
|
+ return LEVEL_02;
|
|
|
+ }
|
|
|
+ return LEVEL_HIGH;
|
|
|
+ }
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 匹配
|
|
|
+ * @param s
|
|
|
+ * @throws Exception
|
|
|
+ */
|
|
|
+ public static List<String> doMatch (String s) throws Exception{
|
|
|
+ if(s == null || "".equals(s.trim())) throw new RuntimeException("data is empty");
|
|
|
+ if(!isNumber(s.charAt(0)+"")) throw new RuntimeException("data illeagle,start not with a number");
|
|
|
+
|
|
|
+ s = replaceAllBlank(s);
|
|
|
+
|
|
|
+ String each;
|
|
|
+ int start = 0;
|
|
|
+
|
|
|
+ for (int i = 0; i < s.length(); i++) {
|
|
|
+ if(isSymbol(s.charAt(i)+"")){
|
|
|
+ each = s.charAt(i)+"";
|
|
|
+ //栈为空，(操作符，或者 操作符优先级大于栈顶优先级 && 操作符优先级不是( )的优先级 及是 ) 不能直接入栈
|
|
|
+ if(stack.isEmpty() || LEFT.equals(each)
|
|
|
+ || ((calcLevel(each) > calcLevel(stack.peek())) && calcLevel(each) < LEVEL_HIGH)){
|
|
|
+ stack.push(each);
|
|
|
+ }else if( !stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek())){
|
|
|
+ //栈非空，操作符优先级小于等于栈顶优先级时出栈入列，直到栈为空，或者遇到了(，最后操作符入栈
|
|
|
+ while (!stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek()) ){
|
|
|
+ if(calcLevel(stack.peek()) == LEVEL_HIGH){
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ data.add(stack.pop());
|
|
|
+ }
|
|
|
+ stack.push(each);
|
|
|
+ }else if(RIGHT.equals(each)){
|
|
|
+ // ) 操作符，依次出栈入列直到空栈或者遇到了第一个)操作符，此时)出栈
|
|
|
+ while (!stack.isEmpty() && LEVEL_HIGH >= calcLevel(stack.peek())){
|
|
|
+ if(LEVEL_HIGH == calcLevel(stack.peek())){
|
|
|
+ stack.pop();
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ data.add(stack.pop());
|
|
|
+ }
|
|
|
+ }
|
|
|
+ start = i ; //前一个运算符的位置
|
|
|
+ }else if( i == s.length()-1 || isSymbol(s.charAt(i+1)+"") ){
|
|
|
+ each = start == 0 ? s.substring(start,i+1) : s.substring(start+1,i+1);
|
|
|
+ if(isNumber(each)) {
|
|
|
+ data.add(each);
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+ throw new RuntimeException("data not match number");
|
|
|
+ }
|
|
|
+ }
|
|
|
+ //如果栈里还有元素，此时元素需要依次出栈入列，可以想象栈里剩下栈顶为/，栈底为+，应该依次出栈入列，可以直接翻转整个stack 添加到队列
|
|
|
+ Collections.reverse(stack);
|
|
|
+ data.addAll(new ArrayList<>(stack));
|
|
|
+
|
|
|
+ System.out.println(data);
|
|
|
+ return data;
|
|
|
+ }
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 算出结果
|
|
|
+ * @param list
|
|
|
+ * @return
|
|
|
+ */
|
|
|
+ public static Double doCalc(List<String> list){
|
|
|
+ Double d = 0d;
|
|
|
+ if(list == null || list.isEmpty()){
|
|
|
+ return null;
|
|
|
+ }
|
|
|
+ if (list.size() == 1){
|
|
|
+ System.out.println(list);
|
|
|
+ d = Double.valueOf(list.get(0));
|
|
|
+ return d;
|
|
|
+ }
|
|
|
+ ArrayList<String> list1 = new ArrayList<>();
|
|
|
+ for (int i = 0; i < list.size(); i++) {
|
|
|
+ list1.add(list.get(i));
|
|
|
+ if(isSymbol(list.get(i))){
|
|
|
+ Double d1 = doTheMath(list.get(i - 2), list.get(i - 1), list.get(i));
|
|
|
+ list1.remove(i);
|
|
|
+ list1.remove(i-1);
|
|
|
+ list1.set(i-2,d1+"");
|
|
|
+ list1.addAll(list.subList(i+1,list.size()));
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ doCalc(list1);
|
|
|
+ return d;
|
|
|
+ }
|
|
|
+
|
|
|
+ /**
|
|
|
+ * 运算
|
|
|
+ * @param s1
|
|
|
+ * @param s2
|
|
|
+ * @param symbol
|
|
|
+ * @return
|
|
|
+ */
|
|
|
+ public static Double doTheMath(String s1,String s2,String symbol){
|
|
|
+ Double result ;
|
|
|
+ switch (symbol){
|
|
|
+ case ADD : result = Double.valueOf(s1) + Double.valueOf(s2); break;
|
|
|
+ case MINUS : result = Double.valueOf(s1) - Double.valueOf(s2); break;
|
|
|
+ case TIMES : result = Double.valueOf(s1) * Double.valueOf(s2); break;
|
|
|
+ case DIVISION : result = Double.valueOf(s1) / Double.valueOf(s2); break;
|
|
|
+ default : result = null;
|
|
|
+ }
|
|
|
+ return result;
|
|
|
+
|
|
|
+ }
|
|
|
+
|
|
|
+ public static void main(String[] args) {
|
|
|
+ String math = "9+(3-1)*3+10/2";
|
|
|
+ //String math = "12.8 + (2 - 3.55)*4+10/5.0";
|
|
|
+ try {
|
|
|
+ doCalc(doMatch(math));
|
|
|
+ } catch (Exception e) {
|
|
|
+ e.printStackTrace();
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+}
|
|
|
+
|
UI