算法 1.3.44 文本编辑器的缓冲区

最新推荐文章于 2021-12-28 17:41:47 发布

原创最新推荐文章于 2021-12-28 17:41:47 发布 · 777 阅读

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本文介绍了一个简单的文本缓冲区编辑器的实现方法，通过两个栈来分别存储光标前后的字符，支持插入、删除、左右移动等基本操作。文章通过具体示例展示了如何使用该编辑器进行文本编辑。

package Cap1;

import java.util.Iterator;

import edu.princeton.cs.introcs.StdOut;

public class Buffer implements Iterable{

	Stack<Character> front = new Stack<Character>(); // 光标前面的
	Stack<Character> after = new Stack<Character>(); // 光标后面的
	public int size(){ return front.size() + after.size(); }
	public void insert(char c){
		front.push(c);
	}
	public char delete(){
		char ans = front.pop();
		return ans;
	}
	public void left(int k){
		if(k>=front.size()) return;
		for(int i=0;i<k;i++)
			after.push(front.pop());
	}
	public void right(int k){
		if(k>after.size()) return;
		for(int i=0;i<k;i++)
			front.push(after.pop());
	}
	@Override
	public Iterator iterator() {
		// TODO Auto-generated method stub
		return new BufferIterator();
	}
	private class BufferIterator implements Iterator{

		
		Iterator<Character> it;
		public BufferIterator(){
			Stack<Character> afterTemp = Stack.copy(after);
			for(Character c:front)
				afterTemp.push(c);
			it = afterTemp.iterator();	
		}
		@Override
		public boolean hasNext() {
			// TODO Auto-generated method stub
			return it.hasNext();
		}

		@Override
		public Character next() {
			// TODO Auto-generated method stub
			return it.next();
		}

		@Override
		public void remove() {
			// TODO Auto-generated method stub
			
		}
		
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Buffer b = new Buffer();
		String s = "Hellow word!";
		for(int i=0;i<s.length();i++){
			b.insert(s.charAt(i));
		}
		for(Object c:b)
			StdOut.print(c);
		StdOut.println();
		b.left(6);
		b.delete();
		for(Object c:b)
			StdOut.print(c);
		StdOut.println();
		b.right(4);
		b.insert('l');
		for(Object c:b)
			StdOut.print(c);
		StdOut.println();
	}
	

}

Hellow word!
Hello word!
Hello world!