[数据结构]Stack

Stack.java

public interface Stack {public void push(Object obj)throws Exception;public Object pop() throws Exception;public Object getTop() throws Exception;public boolean notEmpty();}

SeqStack.java

public class SeqStack implements Stack {final int defaultSize=10;int top;Object[] stack;int maxStackSize;public Object getTop() throws Exception {if(top==0){throw new Exception("Stack is Empty!!!");}return stack[top-1];}public boolean notEmpty() {return top>0;}public Object pop() throws Exception {if(top==0){throw new Exception("Stack is Empty");}top--;return stack[top];}public void push(Object obj) throws Exception {if(top==maxStackSize){throw new Exception("Stack is full!!!");}stack[top]=obj;top++;}protected Object clone() throws CloneNotSupportedException {// TODO 自动生成方法存根return super.clone();}public SeqStack(int sz) {initiate(sz);}public SeqStack() {initiate(defaultSize);}public void initiate(int sz){maxStackSize=sz;top=0;stack=new Object[sz];}}

LinStack.java

public class LinStack implements Stack {Node head;int size;public Object getTop() throws Exception {return head.element;}public boolean notEmpty() {return head !=null;}public Object pop() throws Exception {if(size==0){throw new Exception();}Object obj=head.element;head=head.next;size--;return obj;}public void push(Object obj) throws Exception {head=new Node(obj,head);size++;}public LinStack() {head=null;size=0;}}

 

The tester

public class Exp2_stack97531 {public static void main(String[] args) {try {SeqStack myStack =new SeqStack(),myStack2 =new SeqStack();System.out.println("运用顺序stack");for(int i=1;i<=9;i=i+2){//压入myStack.push(new Integer(i));}while(myStack.notEmpty()){//弹出并压入新stackmyStack2.push(myStack.pop());System.out.println(myStack2.getTop());}myStack=myStack2;//对原来的stack逆序}catch (Exception e) {e.printStackTrace();}}}

中缀转后缀表达式什么的,好像是抄的,好像没完成.

public class middle2Last {String inputStr="";String outputStr="";SeqStack stack=new SeqStack();/** * variables *//** * Methods * */public static void main(String[] args) {// TODO 自动生成方法存根}public middle2Last(String strIn) {this.inputStr=strIn;}/** * * 转换成后缀 */public String trans2last(){try{byte b2='#';stack.push(new Byte(b2));byte[] b=inputStr.getBytes();for(int i=0;i<b.length ;i++){if(!ifCalcNum(b[i])){stack.push(new Byte(b[i]));}else{}}}catch(Exception e){e.printStackTrace();}return outputStr;}/** * 判断是否为计算数 * */boolean ifCalcNum(byte in){switch(in){case '+':return true;case '-':return true;case '*':return true;case '/':return true;}return false;}}

PostExpression.java

有极少数的<1%的代码在其他地方又重新写了,所以这个时候没有完成的版本.

import java.io.*;public class PostExpression {/** * @param args */public static void main(String[] args) {// TODO 自动生成方法存根}public static void postExp(LinStack s) throws Exception {char ch;int x1,x2,b=0;System.out.println("输入后缀表达式#号end");while((ch=(char)(b=System.in.read()))!='#'){if(Character.isDigit(ch)){s.push(new Integer(Character.toString(ch)));}else{x2=((Integer)s.pop()).intValue();x1=((Integer)s.pop()).intValue();switch(ch){case '+':x1+=x2;break;case '-':x1-=x2;break;case '*':x1*=x2;break;case '/':if(x2==0){throw new Exception("除数:0");}else{x1/=x2;break;}}s.push(new Integer(x1));}}System.out.println();}}