稀疏数组

稀疏数组

package array;
import java.util.Arrays;
public class Sparse {
    public static void main(String[] args) {
        //创建二维数组
        System.out.println("遍历原数组:");
        int[][] arrays1 = new int[11][11];
        arrays1[1][2] = 1;
        arrays1[2][3] = 2;
        for (int[] ints : arrays1) {
            for (int anInt : ints) {
                System.out.print(anInt+"  ");
            }
            System.out.println();
        }


        //转化为稀疏数组

        //计算有效值个数
        int sum = 0;
        for (int i = 0; i < arrays1.length; i++) {
            for (int j = 0; j < arrays1[i].length; j++) {
                if(arrays1[i][j] != 0){
                    ++sum;
                }
            }
        }
        System.out.println("有效值个数为:"+sum);
        //创建稀疏数组
        int[][] arrays2 = new int[sum+1][3];//sum+1是为了增加头部显示行、列、值的个数综合；3是为了表示有效值和对应的坐标
        arrays2[0][0] = arrays1.length;
        arrays2[0][1] = arrays1[1].length;
        arrays2[0][2] = sum;
        int temp = 1;//用于计算储存的数据下标
        for (int i = 0; i < arrays1.length; i++) {
            for (int j = 0; j < arrays1[i].length; j++) {
                if(arrays1[i][j] != 0){
                    arrays2[temp][2] = arrays1[i][j];
                    arrays2[temp][1] = j;
                    arrays2[temp][0] = i;
                    ++temp;
                }
            }
        }
        System.out.println("遍历稀疏数组:");
        //遍历稀疏数组
        for (int i = 0; i < arrays2.length; i++) {
            for (int j = 0; j < arrays2[i].length; j++) {
                System.out.print(arrays2[i][j]+"    ");
            }
            System.out.println();
        }


        //将稀疏数组还原为原数组
        int[][] arrays3 = new int[arrays2[0][0]][arrays2[0][1]];
        for (int i = 1; i < arrays2.length; i++) {
            arrays3[arrays2[i][0]][arrays2[i][1]] = arrays2[i][2];
        }
        System.out.println("遍历解析后的数组:");
        for (int[] ints : arrays3) {
            for (int anInt : ints) {
                System.out.print(anInt+"  ");
            }
            System.out.println();
        }


    }
}