记得看数据结构教材，有关稀疏数组介绍很全
话不多说，直接上代码：

package com.zdz.array;

public class ArrayDemo1 {
    public static void main(String[] args) {
        //1.创建一个二维数组 11*11 稀疏数组
        int[][] array1=new int[11][11];
        array1[1][2]=1;
        array1[2][3]=2;
        //输出原始的数组
        System.out.println("原始数组：");
        for (int[] ints : array1) {
            for (int anInt : ints) {
                System.out.print(anInt+"\t");
            }
            System.out.println();
        }
        System.out.println("================================");
        //获取有效值个数
        int sum=0;
        for (int i = 0; i < array1.length; i++) {
            for (int j = 0; j < array1[i].length; j++) {
                if (array1[i][j]!=0){
                    sum++;
                }
            }
        }
        System.out.println("有效值个数："+sum);

        //2.创建一个稀疏数组表
        int[][] array2=new int[sum+1][3];

        array2[0][0]=array1.length;
        array2[0][1]=array1[0].length;
        array2[0][2]=sum;

        //遍历二维数组，将非零的值，存放进数组表中
        int count=0;
        for (int i = 0; i < array1.length; i++) {
            for (int j = 0; j < array1[i].length; j++) {
                if (array1[i][j]!=0){
                    count++;
                    array2[count][0]=i;
                    array2[count][1]=j;
                    array2[count][2]=array1[i][j];
                }
            }
        }
        //输出稀疏数组表
        System.out.println("稀疏数组：");

        for (int i = 0; i < array2.length; i++) {
            System.out.println(array2[i][0]+"\t"
                    + array2[i][1]+"\t"
                    + array2[i][2]+"\t");
        }

        //还原
        System.out.println("================================");
        System.out.println("还原：");
        //1.读取稀疏数组
        int[][] array3=new int[array2[0][0]][array2[0][1]];
        //2.给元素赋值还原
        for (int i = 1; i < array2.length; i++) {
            array3[array2[i][0]][array2[i][1]]=array2[i][2];
        }
        //3.打印
        System.out.println("还原数组：");
        for (int[] ints : array3) {
            for (int anInt : ints) {
                System.out.print(anInt+"\t");
            }
            System.out.println();
        }
    }
}