2025-01-14 1.优化栈类（支持多种类型） 2.逆波兰表达式计算

src/dataANDcalc/java/stack/ArrayStack.java

@@ -2,19 +2,20 @@ package stack;
 
 import queue.ArrayQueue;
 
+import java.util.Objects;
 import java.util.Scanner;
 
-public class ArrayStack {
+public class ArrayStack<E> {
 
     private int top = -1;
 
     private int maxSize;
 
-    private int[] stack;
+    private Object[] stack;
 
     public ArrayStack(int maxSize) {
         this.maxSize = maxSize;
-        stack = new int[maxSize];
+        stack = new Object[maxSize];
     }
 
     public int getTop() {
@@ -33,11 +34,11 @@ public class ArrayStack {
         this.maxSize = maxSize;
     }
 
-    public int[] getStack() {
+    public Object[] getStack() {
         return stack;
     }
 
-    public void setStack(int[] stack) {
+    public void setStack(Object[] stack) {
         this.stack = stack;
     }
 
@@ -58,20 +59,20 @@ public class ArrayStack {
         stack[top] = data;
     }
 
-    public int pop(){
+    public E pop(){
         if(isEmpty()){
             throw new RuntimeException("栈空了");
         }
-        int value = stack[top];
+        E value = (E) stack[top];
         top --;
         return value;
     }
 
-    public int top(){
+    public E top(){
         if(isEmpty()){
             throw new RuntimeException("栈空了");
         }
-        int value = stack[top];
+        E value = (E) stack[top];
         return value;
     }
 
@@ -85,7 +86,7 @@ public class ArrayStack {
     }
 
     public static void main(String[] args) {
-        ArrayStack arrayStack = new ArrayStack(5);
+        ArrayStack<Integer> arrayStack = new ArrayStack(5);
         Scanner scan = new Scanner(System.in);
         while (true) {
             System.out.println("a存数, g取数, s查看, exit退出:");

src/dataANDcalc/java/stack/CalculatorByStack.java

@@ -13,9 +13,9 @@ public class CalculatorByStack {
 
     private final static int DIV = 4;
 
-    private ArrayStack numStack = new ArrayStack(10);
+    private ArrayStack<Integer> numStack = new ArrayStack(10);
 
-    private ArrayStack operStack = new ArrayStack(10);
+    private ArrayStack<Integer> operStack = new ArrayStack(10);
 
     public void calculate(String expression) {
         int length = expression.length();

src/dataANDcalc/java/stack/ReversePoland.java

@@ -0,0 +1,83 @@
+package stack;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+import java.util.Stack;
+import java.util.regex.Pattern;
+
+public class ReversePoland {
+
+    private ArrayStack<Integer> numStack = new ArrayStack(10);
+
+    private List<String> expressList = new ArrayList<>();
+
+    public int calculate(String expression){
+        translateExpress(expression);
+        int length = expressList.size();
+        String operRegex = "[+\\-*/]";
+        Pattern operPattern = Pattern.compile(operRegex);
+        for (int i = 0; i<length;i++){
+            String str = expressList.get(i);
+            if (operPattern.matcher(str).matches()) {
+                if("+".equals(str)){
+                    int num1 = numStack.pop();
+                    int num2 = numStack.pop();
+                    int result = num1 + num2;
+                    numStack.push(result);
+                }
+                if("-".equals(str)){
+                    int num1 = numStack.pop();
+                    int num2 = numStack.pop();
+                    int result = num2 - num1;
+                    numStack.push(result);
+                }
+                if("*".equals(str)){
+                    int num1 = numStack.pop();
+                    int num2 = numStack.pop();
+                    int result = num2 * num1;
+                    numStack.push(result);
+                }
+                if("/".equals(str)){
+                    int num1 = numStack.pop();
+                    int num2 = numStack.pop();
+                    int result = num2/num1;
+                    numStack.push(result);
+                }
+            } else {
+                numStack.push(Integer.parseInt(expressList.get(i)));
+            }
+        }
+
+        return numStack.pop();
+    }
+
+    public void translateExpress(String expression){
+        String[] strArr = expression.split(";");
+        for (String str : strArr){
+            expressList.add(str);
+        }
+    }
+
+    public static void main(String[] args) {
+        ReversePoland reversePoland = new ReversePoland();
+        Scanner scan = new Scanner(System.in);
+        while (true) {
+            System.out.println("c计算, s查看, exit退出:");
+            String handle = scan.next();
+            if ("exit".equals(handle)){
+                break;
+            }
+            if ("c".equals(handle)){
+                System.out.println("请输入计算表达式:");
+                String expression = scan.next();
+                int calculate = reversePoland.calculate(expression);
+                System.out.println("计算结果为:" + calculate);
+            }
+            if ("s".equals(handle)){
+
+            }
+        }
+        scan.close();
+    }
+}