归并算法

public class 归并算法 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[]A= {5,3,1,7,2,9,4};
		int[]temp=new int[A.length];
		MergeSort(A, temp, 0, A.length-1);
		System.out.println("result:");
		for (int i = 0; i < A.length; i++) {
			System.out.println(A[i]+",");
		}
	}
	public static void MergeSort(int[]A,int[]temp,int left,int right) {
		int mid=(left+right)/2;
		if (right<=left) return;
		MergeSort(A, temp, left, mid);
		MergeSort(A, temp, mid+1, right);
		Merge(A,temp,left,mid,right);
		
	}
	public static void Merge(int[]A,int[]temp,int left,int mid,int right){
		
		int i=left,j=mid+1;
		for (int k = left; k<=right;k++) {
			temp[k]=A[k];
		}
		for (int k = left; k <=right; k++) {
			if(i>mid) A[k]=temp[j++];
			else if(j>right) A[k]=temp[i++];
			else if(i>mid) A[k]=temp[j++];
			else if (temp[i]<temp[j])A[k]=temp[i++];
			else A[k]=temp[j++];
		}
			
	}

}