數據結構與算法10-棧和隊列

 棧因爲是臨時存儲，因此一般大小很小

StackX類方法：

構造方法根據參數規定的容量建立一個新棧，棧的域包括表示最大容量的變量。數組自己以及變量top，他存儲棧頂元素的下標。

push()方法：

將top自增一，使它指向原頂端數據項上面的一個位置。並在這個位置上存儲一個數據項。再次提醒，top是插入數據項以前遞增的。

pop()方法：

返回top標識的數據項值，而後top減一。

class StackX {
	private int maxSize;
	private long[] stackArray;
	private int top;
	public StackX(int s)
	{
		maxSize = s;
		stackArray = new long[maxSize];
		top = -1;
	}
	public void push(long j)
	{
		stackArray[++top] = j;
	}
	public long pop()
	{
		return stackArray[top--];
	}
	public long peek()
	{
		return stackArray[top];
	}
	public boolean isEmpty()
	{
		return (top == -1);
	}
	public boolean isFull() {
		return (top == maxSize-1);
	}
}
class StackApp
{
	public static void main(String[] args) {
		StackX theStack = new StackX(10);
		theStack.push(10);
		theStack.push(20);
		theStack.push(30);
		theStack.push(40);
		while(!theStack.isEmpty())
		{
			long value = theStack.pop();
			System.out.print(value);
			System.out.print(" ");
		}
		System.out.println("end");
	}
}

40 30 20 10 end

單詞逆序：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class StackX1 {
	private int maxSize;
	private long[] stackArray;
	private int top;
	public StackX1(int s)
	{
		maxSize = s;
		stackArray = new long[maxSize];
		top = -1;
	}
	public void push(long j)
	{
		stackArray[++top] = j;
	}
	public long pop()
	{
		return stackArray[top--];
	}
	public long peek()
	{
		return stackArray[top];
	}
	public boolean isEmpty()
	{
		return (top == -1);
	}
	public boolean isFull() {
		return (top == maxSize-1);
	}
}
class Reverser
{
	private String input;
	private String output;
	public Reverser(String in)
	{
		input = in;
	}
	public String doRev()
	{
		int StackSize = input.length();
		StackX1 theStack = new StackX1(StackSize);
		for(int j=0;j<input.length();j++)
		{
			char ch = input.charAt(j);
			theStack.push(ch);
		}
		output = " ";
		while(!theStack.isEmpty())
		{
			char ch = (char) theStack.pop();
			output = output + ch;
		}
		return output;
	}
	}
class ReverseApp
{
	public static void main(String[] args) throws IOException {
		String input,output;
		while(true)
		{
			System.out.print("enter");
			System.out.flush();
			input = getString();
			if(input.equals(" "))
				break;
			Reverser theReverser = new Reverser(input);
			output = theReverser.doRev();
			System.out.println(output);
		}
	}

	private static String getString() throws IOException{
		// TODO Auto-generated method stub
		InputStreamReader isr = new InputStreamReader(System.in);
		BufferedReader br = new BufferedReader(isr);
		String s = br.readLine();
		return s;
	}

	
}

enter kdjfklajkfaj
 jafkjalkfjdk 
enter klda;kflakf;kfa
 afk;fkalfk;adlk 
enter