public static void merge(int[] a, int[]b ) throws InterruptedException {

		int[] c = new int[a.length+b.length];
		
		/**
		 * 1,2,5,7
		 * 3,4,6,8
		 */
		
		Thread t1 = new Thread(()->{
			for(int i = 0; i<a.length; i++) {
				int rank = rank(a[i],b);
				System.out.print(rank+i);
				c[rank+i] = a[i];
			}
		});
		
		Thread t2 = new Thread(() -> {
			for(int i = 0; i<b.length; i++) {
				int rank = rank(b[i],a);
				System.out.print(rank+i);
				c[rank+i] = b[i];
			}
		});
		
		t1.start();
		t2.start();
		Thread.sleep(2000);
		
		
		System.out.println(Arrays.toString(c));
	}
	
	public static int rank (int a, int[] arr) { //O(Log(n))
		int left = 0;
		int right = arr.length;
		
		while(left<right) {
			int mid = left + (right - left)/2;
			if(a < arr[mid]) {
				right = mid;
			} else {
				left = mid+1;
			}
		}
		return left;
	}