稀疏数组的实现

稀疏数组的实现

public class SparseArray {
    public static void main(String[] args) {
        //创建一个原始的二维数组11*11
        //0：表示没有棋子，1表示黑子2表示蓝子
        int chessArr1[][] = new int[11][11];
        chessArr1[1][2] = 1;
        chessArr1[2][3] = 2;
        chessArr1[4][2] = 1;
        chessArr1[5][3] = 2;
        //输出原始的二维数组
        System.out.println("原始的二维数组：");
        for (int[] row : chessArr1){
            for (int data: row){
                System.out.printf("%d\t", data);
            }
            System.out.println();
        }

        //将二维数组转稀疏数组
        //1 先遍历二维数组 得到非0数据个数
        int sum=0;//用于记录非零数据个数
        for (int i = 0; i < 11; i++){
            for (int j = 0; j< 11; j++){
                if (chessArr1[i][j] != 0){
                    sum++;
                }
            }
        }

        //2创建对应的稀疏数组
        int sparseArr[][] = new int[sum + 1][3];
        //给稀疏数组赋值
        sparseArr[0][0] = 11;
        sparseArr[0][1] = 11;
        sparseArr[0][2] = sum;

        //遍历二维数组，将非零的值放到sparseArr中
        int count = 0;//count用于记录是第几个非零数据
        for (int i = 0; i < 11; i++){
            for (int j = 0; j< 11; j++){
                if (chessArr1[i][j] != 0){
                    count++;
                    sparseArr[count][0] = i;
                    sparseArr[count][1] = j;
                    sparseArr[count][2] = chessArr1[i][j];
                }
            }
        }

        //输出稀疏数组的格式
        System.out.println();
        StringBuffer stringBuffer = new StringBuffer();
        System.out.println("得到的稀疏数组：");
        for (int i = 0; i < sparseArr.length; i++){
            System.out.printf("%d\t%d\t%d\t\n", sparseArr[i][0],sparseArr[i][1],sparseArr[i][2]);
            stringBuffer.append(Integer.toString(sparseArr[i][0]) + " " + Integer.toString(sparseArr[i][1]) + " " + Integer.toString(sparseArr[i][2]) + "\n");
//            String string = Integer.toString(sparseArr[i][0]) + Integer.toString(sparseArr[i][1]) + Integer.toString(sparseArr[i][2]);
        }
        System.out.println();
        File file = new File("D:\\code\\spring\\DataStructures\\src\\main\\java\\com\\wpc\\sparseArray\\map.data");
        OutputStream outputStream = null;
        try{
             outputStream = new FileOutputStream(file);
            outputStream.write(stringBuffer.toString().getBytes());
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            try {
                outputStream.close();
            }catch (IOException e){
                e.printStackTrace();
            }
        }



        try {
            BufferedReader reader = new BufferedReader(new FileReader("D:\\code\\spring\\DataStructures\\src\\main\\java\\com\\wpc\\sparseArray\\map.data"));
            String line = null;
            line = reader.readLine();
            String[] strings = line.split("\\s");
            int[][] sparseArr3 = new int[Integer.parseInt(strings[0])][Integer.parseInt(strings[1])];
            while ((line = reader.readLine()) != null){
                String[] strings2 = line.split("\\s");
                sparseArr3[Integer.parseInt(strings2[0])][Integer.parseInt(strings2[1])] = Integer.parseInt(strings2[2]);
            }
            for (int[] row : sparseArr3){
                for (int i : row){
                    System.out.printf("%d\t",i);
                }
                System.out.println();
            }
            System.out.println("文件读取输出");
        }catch (IOException e){
            e.printStackTrace();
        }



        //将稀疏数组返回为原有数组

        /*
        * 1.先读取稀疏数组的第一行，根据第一行数据，创建二维数组，比如chessArr2 = int[][]
        * 2.在读取稀疏数组后几行的数据，并赋给原始的二维数组即可
        * */

        //1.先读取稀疏数组的第一行，根据第一行数据，创建二维数组

        int chessArr2[][] = new int[sparseArr[0][0]][sparseArr[0][1]];

        //2.在读取稀疏数组后几行的数据，并赋给原始的二维数组即可
        for (int i = 1; i < sparseArr.length; i++){
            chessArr2[sparseArr[i][0]][sparseArr[i][1]] = sparseArr[i][2];
        }

        //输出恢复后的二维数组
        for (int[] row : chessArr2){
            for (int data : row){
                System.out.printf("%d\t", data);
            }
            System.out.println();
        }

    }
}

结果输出

原始的二维数组：
0	0	0	0	0	0	0	0	0	0	0	
0	0	1	0	0	0	0	0	0	0	0	
0	0	0	2	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	1	0	0	0	0	0	0	0	0	
0	0	0	2	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	

得到的稀疏数组：
11	11	4	
1	2	1	
2	3	2	
4	2	1	
5	3	2	

0	0	0	0	0	0	0	0	0	0	0	
0	0	1	0	0	0	0	0	0	0	0	
0	0	0	2	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	1	0	0	0	0	0	0	0	0	
0	0	0	2	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
文件读取输出
0	0	0	0	0	0	0	0	0	0	0	
0	0	1	0	0	0	0	0	0	0	0	
0	0	0	2	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	1	0	0	0	0	0	0	0	0	
0	0	0	2	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0	
0	0	0	0	0	0	0	0	0	0	0