对称矩阵与压缩存储算法（java实现）

package 数组和矩阵;
public class DuiChenJuZhenYaSuo {
	int[] arr;
	int order; //矩阵的阶数
	int n; //压缩后一位数组的个数
	public DuiChenJuZhenYaSuo(int order) {
		this.n= order * (order + 1) / 2;
		this.arr = new int[this.n];
		this.order = order;
	}
	public void init(int[][] a) {
		int k = 0;
		for (int i = 0; i < order; i++) {
			for (int j = 0; j <= i; j++) {
				arr[k++] = a[i][j];
			}
		}
	}
	public void init(int[] a) {
		for (int i = 0; i < n; i++) {
			arr[i] = a[i];
		}
	}
	public void print() {
		int k;
		for (int i = 1; i <= order; i++) {
			for (int j = 1; j <= order; j++) {
				k= (i >= j) ? (i * (i - 1) / 2 + j - 1) : (j * (j - 1) / 2 + i - 1);
				System.out.print(arr[k] + " ");
			}
			System.out.println();
		}
	}
	public DuiChenJuZhenYaSuo merge(DuiChenJuZhenYaSuo a) {
		DuiChenJuZhenYaSuo test = new DuiChenJuZhenYaSuo(this.order);
		int k;
		for (int i = 1; i <= order; i++) {
			for (int j = 1; j <= order; j++) {
				k = (i >= j) ? (i * (i - 1) / 2 + j - 1) : (j * (j - 1) / 2 + i - 1);
				test.arr[k] = this.arr[k] + a.arr[k];
			}
		}
		return test;
	}
	public static void main(String[] args) {
		DuiChenJuZhenYaSuo test = new DuiChenJuZhenYaSuo(3);
		DuiChenJuZhenYaSuo test2 = new DuiChenJuZhenYaSuo(3);
		int[][] a = { { 1, 0, 0 }, { 2, 3, 0 }, { 4, 5, 6 } };
		int[] b= {1,2,3,4,5,6};
		test.init(b);
		test2.init(a);
		test = test.merge(test2);
		test.print();
	}
}