使用数据结构实现计算器功能－java

java 代码

package cacu;
/**
 * myejb6.0 CacuStack.java
 */

/**
 * @author sunxboy
 *
 * 10:19:05 AM May 30, 2007
 */
public class CacuStack {

    CacuNode top;

    public CacuStack() {
        top = null;
    }

    public boolean isEmpty() {

        return top==null;
    }

    public boolean push(int data) {
        CacuNode node = new CacuNode(data);
        if(isEmpty()) {
            top = node;
            return true;
        }else {
            node.next=top;
            top = node;
            return true;
        }

    }

    public int pop() {
        int data = top.data;
        top = top.next;
        return data;
    }

    public static void main(String[] args) {

        CacuStack stack=new CacuStack ();
        stack.push(1);
        stack.push(2);
        stack.push(3);
        stack.push(4);
        stack.pop();
        stack.pop();
        while(!stack.isEmpty())
        {
            System.out.println(stack.pop());
        }
    }
}

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java 代码

/**
 *
 */
package cacu;

/**
 * @author sunxboy
 *
 */
public class Cacu {

    CacuStack cs;

    public int cacu(String source) {
        cs = new CacuStack();
        for (int i = 0; i < source.length(); i++) {
            char ch = source.charAt(i);
            // 如果是数字
            if (ch <= '9' && ch >= '0') {
                cs.push(Integer.parseInt(ch+""));   //注意这里不能用Integer.valueOf(ch);
            } else {
                int num2 = cs.pop();
                int num1 = cs.pop();
                switch (ch) {
                case '+':
                    cs.push(num1+num2);
                    break;
                case '-':
                    cs.push(num1-num2);
                    break;
                case '*':
                    cs.push(num1*num2);
                    break;
                case '/':
                    cs.push(num1/num2);
                    break;

                }
            }
        }
        return cs.pop();
    }

    public static void main(String[] args) {
        InToPost post=new InToPost();
        Cacu cacu=new Cacu();
    //  (a+b*c)*(e+f+m+n*j)
//      System.out.println(post.doTrans("1+1"));
//      System.out.println(cacu.cacu(post.doTrans(("1+1"))));
        System.out.println(post.doTrans("(9+2*7)*(5+6+8+9*5)"));
        System.out.println(cacu.cacu(post.doTrans("(9+2*7)*(5+6+8+9*5)")));

    }
}

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java 代码

/**
 *
 */
package cacu;

/**
 * @author sunxboy
 *
 */
public class CacuNode {

    int data;
    CacuNode next;
    public CacuNode(int data) {
        this.data = data;
    }
}

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java 代码

/**
 * struture Stack.java
 */
package cacu;

/**
 * @author sunxboy
 *
 * 10:20:22 AM May 30, 2007
 */
public class Stack {

    private Node top;
    public Stack() {
        top=null;
    }

    public boolean push(char data) {
        Node newNode = new Node(data);
        if(isEmpty()) {
            top= newNode;
            return true;
        }else {
            newNode.next = top;
            top = newNode;
            return true;
        }
    }

    public char pop(){
        char data = top.data;
        top =top.next;
        return data;
    }

    public boolean isEmpty() {
        return top==null;
    }

    public static void main(String[] args) {
        Stack stack=new Stack();
        stack.push('a');
        stack.push('b');
        stack.push('c');
        stack.push('d');
        stack.pop();
        stack.pop();
        while(!stack.isEmpty())
        {
            System.out.println(stack.pop());
        }
    }
}

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java 代码

/**
 * struture Node.java
 */
package cacu;

/**
 * @author sunxboy
 *
 * 10:20:13 AM May 30, 2007
 */
public class Node {

    public char data;
    public Node next;
    public Node(char data) {
        this.data = data;
    }
}

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java 代码

/**
 * struture InToPost.java
 */
package cacu;

/**
 * @author sunxboy
 *
 * 10:20:04 AM May 30, 2007
 */
public class InToPost {

    String output = "";

    Stack stack;

    public String doTrans(String source) {

        stack = new Stack();
        for (int i = 0; i < source.length(); i++) {
            char ch = source.charAt(i);
            switch (ch) {
            case '+':
            case '-':
                doOper(ch,1);
                break;
            case '*':
            case '/':
                doOper(ch,2);
                break;
            case '(':
                stack.push(ch);
                break;
            case ')':
                getParent();
                break;
            default:
                output = output + ch;
                break;
            }
        }
//       将栈中全部取出
        while (!stack.isEmpty()) {

            output = output + stack.pop();
        }
        return this.output;
    }

    private void getParent() {
        while(!stack.isEmpty()) {
            char ch = stack.pop();
            if(ch=='('){
                break;
            }else{
                output=output+ch;
            }
        }

    }

    public void doOper(char ch1, int lev) {

        while (!stack.isEmpty()) {
            char popch = stack.pop();
            if (popch == '(') {
                stack.push(popch);
                break;
            } else {
                int lev2;
                if (popch == '+' || popch == '-') {
                    lev2 = 1;
                } else {
                    lev2 = 2;
                }

                // 将栈中取出的与传入的比较优先级
                if (lev > lev2) {
                    stack.push(popch); // 将低级别的放回去
                    break;
                } else {
                    output = output + popch;
                }
            }

        }
        stack.push(ch1);    //将高级别放在外层
    }

    public static void main(String[] args) {
        InToPost post=new InToPost();
        String temp="(a+b*c)*(e+f+m+n*j)";
        //abc*+ef+m+nj*+*
        System.out.println(post.doTrans(temp));

    }

}