• Java数据结构与排序算法——堆和堆排序


    //=================================================
    // File Name       :	Heap_demo
    //------------------------------------------------------------------------------
    // Author          :	Common
    
    //类名:Node_Heap
    //属性:
    //方法:
    class Node_Heap{
    	public int iData;
    
    	public Node_Heap(int iData) {	//构造函数
    		super();
    		this.iData = iData;
    	}
    
    	public int getiData() {
    		return iData;
    	}
    
    	public void setiData(int iData) {
    		this.iData = iData;
    	}
    }
    
    //类名:Heap
    //属性:
    //方法:
    class Heap{
    	private Node_Heap[] heapArray;
    	public int maxSize;
    	private int currentSize;
    	
    	public Heap(int maxSize) {	//构造函数
    		super();
    		this.maxSize = maxSize;
    		this.currentSize = 0;
    		heapArray = new Node_Heap[maxSize];
    	}
    	
    	public boolean isEmpty(){
    		return currentSize ==0;
    	}
    	
    	public boolean insert(int key){
    		if(currentSize == maxSize){
    			return false;
    		}
    		Node_Heap newNode = new Node_Heap(key);	
    		heapArray[currentSize] = newNode;				//把插入的节点放在最后的位置
    		trickleUp(currentSize++);									//插入节点并把currentSize加1
    		return true;
    	}
    	
    	//用于插入,把父类节点下移,然后把插入的节点放到合适的位置
    	public void trickleUp(int index){
    		int parent = (index-1)/2;
    		Node_Heap bottom = heapArray[index];		//暂存新插入的节点,因为需要把父节点下移
    		while(index>0 && heapArray[parent].getiData()<bottom.getiData()){	//如果小,就下移
    			heapArray[index] = heapArray[parent];		//把父类节点下移
    			index = parent;						//用于递归
    			parent = (parent-1)/2;
    		}
    		heapArray[index] = bottom;	//把插入的节点放到合适的位置
    	}
    	
    	public Node_Heap remove(){	//删除最大的节点
    		Node_Heap root = heapArray[0];
    		heapArray[0]=heapArray[--currentSize];
    		trickleDown(0);
    		return root;
    	}
    	
    	//用于删除,把子类节点上移
    	public void trickleDown(int index){
    		int largerChild;
    		Node_Heap top = heapArray[index];		//
    		while(index<currentSize/2){	//如果小,就下移
    			int leftChild = 2*index+1;
    			int rightChild = leftChild+1;
    			if(rightChild<currentSize && heapArray[leftChild].getiData() < heapArray[rightChild].getiData())
    				largerChild = rightChild;
    			else
    				largerChild = leftChild;
    			if(top.getiData()>=heapArray[largerChild].getiData())
    				break;
    			heapArray[index] = heapArray[largerChild];
    			index = largerChild;
    		}
    		heapArray[index] = top;	
    	}
    	
    	public void displayHeap(){
    		System.out.print("heapArray:");
    		for(int i=0;i<heapArray.length;i++){
    			if(heapArray[i] != null)
    				System.out.print(heapArray[i].getiData()+" ");
    			else
    				System.out.print(" -- ");
    		}
    		System.out.println();
    		
    		int nBlanks = 32;			//定义空格
    		int itemsPerRow = 1;
    		int column = 0;
    		int j=0;								//标记当前的数组下标,从0开始
    		System.out.println("......................................................");
    		while(currentSize > 0){
    			if(column == 0){
    				for(int i=0;i<nBlanks;i++){
    					System.out.print(" ");
    				}
    			}
    			System.out.print(heapArray[j].getiData());
    			if(++j == currentSize){
    				break;
    			}
    			if(++column==itemsPerRow){		//如果每一行计数等于这一行的上限,则换行
    				nBlanks /= 2;				//空格数减半
    				itemsPerRow *= 2;		//每一行的上限
    				column = 0;
    				System.out.println();
    			}else{
    				for(int i=0;i<nBlanks*2-2;i++){
    					System.out.print(" ");
    				}
    			}
    		}
    		System.out.println("
    "+"......................................................");
    	}
    	
    }
    
    //主类
    //Function        : 	Heap_demo
    public class Heap_demo {
    
    	public static void main(String[] args) {
    		// TODO 自动生成的方法存根
    		int anArrays[]={1,2,3,4,5,6,7,8,9,10};
    		Heap theHeap = new Heap(31);
    //		theHeap.insert(1);
    //		theHeap.insert(2);
    //		theHeap.insert(3);
    //		theHeap.insert(4);
    //		theHeap.insert(5);
    //		theHeap.insert(6);
    		for(int i=0;i<10;i++){
    			theHeap.insert(anArrays[i]);
    		}
    		theHeap.displayHeap();
    		//theHeap.remove();
    		//theHeap.displayHeap();
    		for(int i=0;i<10;i++){
    			anArrays[i]=theHeap.remove().iData;
    		}
    		for(int i=0;i<10;i++){
    			System.out.print(anArrays[i]+" ");
    		}
    	}
    
    }
    

     

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  • 原文地址:https://www.cnblogs.com/tonglin0325/p/5402347.html
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