JAVA SE稀疏数组

JAVA SE稀疏数组

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1.目的
当一个数组中大部分元素为零时，为了节省空间，可以用稀疏数组保存
2原码

public class ArrayDome08 {
    public static void main(String[] args) {
        int[][]array1 = new int [11][11];
        array1[1][2]=1;
        array1[2][3]=2;
        System.out.println("输出原始数组");
        for (int[] ints:array1) {
            for (int anInt:ints) {
                System.out.print(anInt+"\t");
            }
            System.out.println();
        }
        //输出原始数组
        int sum=0;
        for (int i = 0; i <11 ; i++) {
            for (int j = 0; j <11 ; j++) {
                if (array1[i][j]!=0){
                    sum++;
                }
            }
        }
        System.out.println("有效值个数"+sum);
        //计算有效值个数
        int[][] array2 =new int[sum+1][3];
        array2[0][0]=11;
        array2[0][1]=11;
        array2[0][2]=sum;
        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];
                 }
            }
        }//将数组转换为稀疏数组
        System.out.println("输出稀疏数组");
        for (int i = 0; i <array2.length ; i++) {
            for (int j = 0; j <array2[i].length ; j++) {
                System.out.print(array2[i][j]+"\t");
            }
            System.out.println();
        }//将稀疏数组还原
        System.out.println("还原稀疏数组");

        int[][] array3 =new int[array2[0][0]][array2[0][1]];
        for (int i = 1; i <array2.length ; i++) {
           array3[array2[i][0]][array2[i][1]]=array2[i][2];
        }
        for (int i = 0; i <array3.length ; i++) {
            for (int j = 0; j < array3[i].length; j++) {
                System.out.print(array3[i][j]+"\t");
            }
            System.out.println();
        }

    }
}