java 歸併排序（穩定）

package 快速排序_歸併排序_二分查找_等排序;

public class GuiBIngSort {
	public static void main(String args[]){
		int[] arr = {-3,10,3,4,-1,2,5,6,7,0,1,8,9};
		int[] aaa = new int[arr.length];
		//Sort(arr,aaa,0,arr.length-1);
		mergeSort(arr, 0 , arr.length-1);
		for(int i=0;i<arr.length;i++){
			System.out.println(arr[i]);
		}
	}
	
	
	
	public static void mergeSort(int[] a, int left, int right) {
		         if(left<right){
		            int middle = (left+right)/2;
		            //對左邊進行遞歸
		            mergeSort(a, left, middle);
		            //對右邊進行遞歸
		             mergeSort(a, middle+1, right);
		             //合併
		             merge(a,left,middle,right);
		         }
		     }
	 
		     private static void merge(int[] a, int left, int middle, int right) {
		         int[] tmpArr = new int[a.length];
		        int mid = middle+1; //右邊的起始位置
		        int tmp = left;
		        int third = left;
		         while(left<=middle && mid<=right){
		             //從兩個數組中選取較小的數放入中間數組
		             if(a[left]<=a[mid]){
		                 tmpArr[third++] = a[left++];
		             }else{
		                 tmpArr[third++] = a[mid++];
		             }
		         }
	         //將剩餘的部分放入中間數組
		        while(left<=middle){
		            tmpArr[third++] = a[left++];
		         }
		         while(mid<=right){
		             tmpArr[third++] = a[mid++];
		         }
		         //將中間數組複製回原數組
		         while(tmp<=right){
		            a[tmp] = tmpArr[tmp++];
		         }
		     }
}