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废话不多说,直接上代码, 栈是最简单的数据及结构, 可以使用数组实现也可以用链表实现. 并且有对泛型的支持.接口点击(此处)折叠或打开public interface StackE> { boolean isEmpty(); E peek(); E pop(); void push(E item); int size();}这是个用链表实现的stack.点击(此处)折叠或打开public class GenericLinkedStackE> implements StackE> { private class NodeT>{ private T data; private NodeT> next; private Node(T data,NodeT> next){ this.data=data; this.next=next; } } private NodeE> top; private int size; public void push(E item){ top=new Node(item, top); size++; } public E pop(){ E result=top.data; top=top.next; size--; return result; } public int size(){ return size; } public E peek(){ return top.data; } public boolean isEmpty(){ return size==0; } public static void main(String[] args) { // TODO Auto-generated method stub StackInteger> s = new GenericLinkedStack>(); System.out.println(s.isEmpty()); for(int i=0;i5;i++){ s.push(i); } for(int i=0;i10;i++){ s.push(i); } System.out.println(s.isEmpty()); System.out.println(s.peek()); System.out.println(s.size()); System.out.println(s.pop()); StackDouble> d= new GenericLinkedStack>(); System.out.println(d.isEmpty()); Random gen = new Random(); for(int i=0;i10;i++){ d.push(gen.nextGaussian()); } System.out.println(d.isEmpty()); System.out.println(d.peek()); System.out.println(d.size()); System.out.println(d.pop()); }}下面的是数组的.点击(此处)折叠或打开public class GenericArrayStackE> implements StackE>{ private int top=-1; private E[] data; private static final int DEFAULT_CAPACITY=10; public boolean isEmpty(){ return top==-1; } public int size(){ return data.length; } //constructor public GenericArrayStack(){ data=(E[])new Object[DEFAULT_CAPACITY]; } public E peek(){ return data[top]; } public void push(E elem){ if(top==data.length-1) resize(2*data.length); data[++top]=elem; } public E pop(){ if(isEmpty()) throw new EmptyStackException(); return data[top--]; } public void resize(int newCapacity){ E[] newdata = (E[])new Object[newCapacity]; for(int i=0;i=top;i++){ newdata[i]=data[i]; } data=newdata; } public static void main(String[] args) { // TODO Auto-generated method stub StackInteger> s = new GenericArrayStack>(); System.out.println(s.isEmpty()); for(int i=0;i10;i++){ s.push(i); } System.out.println(s.isEmpty()); System.out.println(s.peek()); System.out.println(s.size()); System.out.println(s.pop()); }}下面是解析算术表达式点击(此处)折叠或打开package tree;public class Expression { private static int rank(String op){ switch(op){ case "*": case "/": return 2; case "+": case "-": return 1; default : return -1; } } private static final String SPACE=" "; public static String toPostfix(String expr){ StringBuilder result = new StringBuilder(); StackString> operators = new GenericArrayStack>(); for(String token: expr.split("\\s+")){ if(rank(token) > 0){ while(!operators.isEmpty() && rank(operators.peek()) >= rank(token)){ result.append(operators.pop()+SPACE); } operators.push(token); }else{ result.append(token+SPACE); } } while(!operators.isEmpty()){ result.append(operators.pop()+SPACE); } return result.toString(); } public static int compute(int i1, int i2, String op){ int result=0; switch(op){ case "*": result = i1 * i2; break; case "/": result = i1 / i2; break; case "+": result = i1 + i2; break; case "-": result = i1 - i2; break; } return result; } public static int evalPostfix(String exp){ //Stack results = new GenericArrayStack(); StackString> operands = new GenericArrayStack>(); int result =0; for(String token: exp.split("\\s+")){ if(rank(token)> 0){ int oper2=Integer.parseInt(operands.pop()); int oper1=Integer.parseInt(operands.pop()); result = compute(oper1, oper2, token); //System.out.println(result); operands.push(Integer.toString(result,10)); }else{ operands.push(token); } } return Integer.parseInt(operands.pop()); } public static void main(String[] args) { // TODO Auto-generated method stub int answer =0; String exp = "3 5 1 - *"; answer = evalPostfix("3 5 1 - *"); System.out.println(answer); String exp2= "5 - 1 + 3 * 2"; System.out.println(evalPostfix(toPostfix(exp2))); }} 10-12 11:23