stack.java

前缀式转后缀式 simplestack是一个接口 stack是栈 suanshu是一个转换的类

public class Stack implements Simplestack{
	int maxSize;
	int top;
	char [] stack;
	final int defualSize=10;
	
	public Stack(){
		initiate(defualSize);
	}
	
	public Stack(int size){
		initiate(size);
	}
	
	public void initiate(int size){
		maxSize =size;
		top=0;
		stack=new char [size];
	}
	public void push(char   obj)throws Exception{
		if(top==maxSize) {
		throw new Exception("all");
		}
		stack[top]=obj;
		top++	;
	}
	public char pop()throws Exception{
		if(top==0) {
		System.out.println (" stack is EMPTY when poping");
		}
		top--;
		return stack[top];	
	}
	public char getTop()throws Exception{
		if(top==0) {
		System.out.println ("stack is EMPTY when getToping");
		}
		return stack[top-1];
	}
	public boolean notEmpty(){
		return(top>0);
	}
}