seqstack.java

来自「java开发的大整数计算器,实现基本的运算,还有sin,cos,tan,cot.」· Java 代码 · 共 49 行

public class SeqStack implements Stack{
	final int defaultSize = 10;
	int top;
	String[] stack;
	int maxStackSize;
	
	public SeqStack(){
		initiate(defaultSize);
	}
	
	public SeqStack(int sz){
		initiate(sz);
	}
	
	private void initiate(int sz){
		maxStackSize = sz;
		top = 0;
		stack = new String[sz];
	}
	
	public void push(String obj) throws Exception{
		if(top == maxStackSize){
			throw new Exception("堆栈已满！");
		}
		stack[top] = obj;
		top ++;
	}
	
	public String pop() throws Exception{
		if(top == 0){
			throw new Exception("堆栈已空！");
		}
		top --;
		return stack[top];
	}
	
	public String getTop() throws Exception{
		if(top == 0){
			throw new Exception("堆栈已空！");
		}
		return stack[top - 1];
	}
	
	public boolean isEmpty(){
		return (top == 0);
	}
	
}