归并排序的java实现

package test;
public class MergeSort {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[] arr = {2,3,6,7,66,77,55,44,66,79,56,37};
		sort(arr);
		System.out.println(arr.length);
		print(arr);
	}
	
	static void print(int arr[]) {
		for (int temp : arr) {
			System.out.printf("%d,",temp);
		}
		System.out.println();
	}
	
	public static void sort(int arr[]) {
		int temp[] = new int[arr.length];
		mergeSort(arr,temp,0,arr.length-1);
	}
	
	private static void mergeSort(int arr[],int temp[],int m,int n) {
		if (m == n) return;
		int mid = (m+n)/2;
		mergeSort(arr, temp, m, mid);
		mergeSort(arr, temp, mid+1, n);
		for (int i = m; i <= n; i++) {
			temp[i] = arr[i];
		}
		int index1 = m;
		int index2 = mid + 1;
		int index = m;
		
		while (index1 <= mid && index2 <= n) {
			if (temp[index1] < temp[index2]) {
				arr[index++] = temp[index1++];
			} else {
				arr[index++] = temp[index2++];
			}
		}
		while(index1 <= mid) {
			arr[index++] = temp[index1++];
		}
		while(index2 <= n) {
			arr[index++] = temp[index2++];
		}
		
	}

}