package com.data.struct;

import java.util.concurrent.CountDownLatch;

public class CopyOfMultiThreadMergeSort2 {
	private static void mergeSort(int [] source,int left,int right,CountDownLatch cdl){
		if(left==right){
			cdl.countDown();
			cdl.countDown();
			return ;
		}else{
			int middle=(left+right)/2;
			MergeSortThread t1=new MergeSortThread(source,left,middle,cdl);
			t1.start();
			MergeSortThread t2=new MergeSortThread(source,middle+1,right,cdl);
			t2.start();
			try {
				cdl.await();
			} catch (InterruptedException e) {
				
			}
			
			int[]tmp=new int[right-left+1];
			int l=0;
			int lindex=left;
			int rindex=middle+1;
			for(;lindex<=middle;){
				if(rindex>right){
					break;
				}
				if(source[lindex]<source[rindex]){
					tmp[l++]=source[lindex];
					lindex++;
				}else{
					tmp[l++]=source[rindex];
					rindex++;
				}
			}
			if(lindex==middle+1&&rindex<=right){
				for(;rindex<=right;rindex++){
					tmp[l++]=source[rindex];
				}
			}
			if(rindex>right&&lindex<=middle){
				for(;lindex<=middle;lindex++){
					tmp[l++]=source[lindex];
				}
			}
			
			l=0;
			for(int x=left;x<=right;x++){
				source[x]=tmp[l++];
			}
			
			for(int i=0;i<source.length;i++){
				System.out.print(source[i]+" ");
			}
			System.out.println();
			
		}
		
	}
	
	private static class MergeSortThread extends Thread{
		private int[]A;
		private int p;
		private int r;
		private CountDownLatch cdl;
		public MergeSortThread(int[]A,int p,int r,CountDownLatch cdl){
			this.A=A;
			this.p=p;
			this.r=r;
			this.cdl=cdl;
		}
		@Override
		public void run() {
			CountDownLatch c=new CountDownLatch(2);
			mergeSort(A,p,r,c);
			try {
				c.await();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			
			this.cdl.countDown();
		}
		
		
	}
	public static void main(String[] args) {
		int[] data=new int[]{4,5,2,9,1,0,7};
		for(int i=0;i<data.length;i++){
			System.out.print(data[i]+" ");
		}
		System.out.println();
		CountDownLatch cd=new CountDownLatch(2);
		mergeSort(data,0,data.length-1,cd);;
		try {
			cd.await();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		for(int i=0;i<data.length;i++){
			System.out.print(data[i]+" ");
		}
		System.out.println();

	}

}