数据结构与算法分析（JAVA版）Chapter1练习题

/**
 * 类名：Test1.java
 * 说明：返回N的二进制的1个个数
 */
public class Test5 {

	public static int getOne(int n){
		if(n < 2)
			return 1;
		return n%2 + getOne(n/2);
	}
	/**
	 * 函数名称：main
	 * 说明：
	 */
	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		
		System.out.println(getOne(255));
	}

}

/**
 * 类名：Test6.java
 * 说明：全排列
 */

public class Test6 {
	public static  void perm(Type[] a){
		perm(a,0,a.length-1);
	}
	private static void perm(Type[]a, int low,int high){
		if(low == high){
			for(int i = 0; i<=high;i++)
				System.out.print(a[i]);
			System.out.println();
		}else{
			for(int i = low;i<=high;i++){
				Type temp = a[low];//和后面的交换
				a[low] = a[i];
				a[i] = temp;
				perm(a,low+1,high);
				Type temp2 = a[low];//换回来
				a[low] = a[i];
				a[i] = temp2;
			}
		}
	}
	public static void main(String[] args) {
		Character[] c = new Character[]{'a','b','c'};
		perm(c);
		
	}
}

class Collection {
	private Object[] o;
	private int size = 0;

	Collection(int size) {
		o = new Object[size];
	}

	public boolean isEmpty(){
		if(size==0)
			return true;
		else
			return false; 
		}
	public boolean insert(T a){
		o[size] = a;
		size++;
		if(size > o.length)
			return false;
		else 
			return true;
	}
	public boolean makeEmpty(){
		size = 0;
		return true;
	}
	public boolean remove(){
		if(size > 0){
			size--;
			return true;
		}else
			return false;
	}
	public boolean isPresent(T x){
		boolean flag = false;
		for(int i = 0;i < size;i++)
			if(x.equals(o[i]))
				flag = true;
		if(flag)
			return true;
		else
			return false;
	}
}

public class Test13 {

	/**
	 * 函数名称：main 说明：测试
	 */
	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		Collection c = new Collection(20);
		c.insert(2);
		c.insert(3);
		System.out.println(c.isPresent(new Integer(3)));
		c.remove();
		System.out.println(c.isPresent(new Integer(3)));
	}

}

/**
 * 类名：Test14.java 
 * 说明：设计一个泛型类OrderedCollection
 */
class OrderedCollection>{
	private Object[] o;
	private int size = 0;

	public OrderedCollection(int size) {
		o = new Object[size];
	}

	public boolean isEmpty() {
		if (size == 0)
			return true;
		else
			return false;
	}

	public boolean makeEmpty() {
		size = 0;
		return true;
	}

	public boolean insert(T a) {
		
		if (size > o.length)
			return false;
		else {
			o[size] = a;
			size++;
			return true;
		}
	}

	public boolean remove() {
		if (size > 0) {
			size--;
			return true;
		} else
			return false;
	}

	public T findMin() {
		if (size == 0)
			return null;
		else {
			T min = (T) o[0];
			for (int i = 1; i < size; i++) {
				if ((((T) o[i]).compareTo(min)) < 0) {
					min = (T) o[i];
				}
			}
			return min;
		}
	}

	public T findMax() {
		if (size == 0)
			return null;
		else {
			int  max = 0;
			for (int i = 1; i < size; i++) {
				if ((((T) o[i]).compareTo((T) o[max])) > 0) {
					max = i;
				}
			}
			return (T)o[max];
		}
	}

}

public class Test14 {

	/**
	 * 函数名称：main 
	 * 说明：测试
	 */
	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		OrderedCollection c = new OrderedCollection(10);
		c.insert(5);
		c.insert(3);
		c.insert(2);
		System.out.println(c.findMax()+" "+c.findMin());
		c.remove();
		System.out.println(c.findMax()+" "+c.findMin());
	}

}

import java.util.Comparator;

class Rectangle {
	private int width;
	private int length;

	public Rectangle(int length, int width) {
		this.width = width;
		this.length = length;
	}

	public int getWidth() {
		return width;
	}

	public int getLength() {
		return length;
	}
	public String toString(){
		return "长方形的长度："+length+"宽度："+width;
	}
}

class AreaComparator implements Comparator {
	@Override
	public int compare(Rectangle o1, Rectangle o2) {
		if (o1.getLength() * o1.getWidth() > o2.getLength() * o2.getWidth())
			return 1;
		else if (o1.getLength() * o1.getWidth() < o2.getLength()
				* o2.getWidth())
			return -1;
		else
			return 0;
	}

}

class PerimeterComparator implements Comparator {

	@Override
	public int compare(Rectangle o1, Rectangle o2) {
		if (o1.getLength() + o1.getWidth() > o2.getLength() + o2.getWidth())
			return 1;
		else if (o1.getLength() + o1.getWidth() < o2.getLength()
				+ o2.getWidth())
			return -1;
		else
			return 0;
	}

}

/***********************************************
 * 类名：Test15.java
 *  说明：写一个Rectangle类，并比较
 ***********************************************/
public class Test15 {

	
	/*************************************************
	 * 函数名称：findMax
	 * 说明：根据不同的比较器找到MAX；
	 *************************************************/
	public static  AnyType findMax(AnyType[] arr,
			Comparator cmp) {
		int max = 0;
		for (int i = 1; i < arr.length; i++) {
			if (cmp.compare(arr[max], arr[i]) < 0)
				max = i;
		}
		return arr[max];
	}

	
	/*************************************************
	 * 函数名称：main
	 * 说明：写一个Rectangle数组，并找到面积和周长最大的对象
	 *************************************************/
	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		Rectangle[] r = new Rectangle[] { new Rectangle(1, 2),
				new Rectangle(5, 5), new Rectangle(6, 5), new Rectangle(4, 6),
				new Rectangle(16, 1), new Rectangle(2, 2) };
		System.out.println("面积最大的为："+findMax(r,new AreaComparator()));
		System.out.println("周长最大的为："+findMax(r,new PerimeterComparator()));
	}

}