数据结构——稀疏数组

数据结构——稀疏数组

棋局存档问题：如何将一局五子棋保存下来，并实现读档

• 利用稀疏数组进行数据保存，IO流写入/读取文件，实现读档。

简单代码实现：

/**
 * @author 萝卜
 * @date 2022/4/6
 * @dec 稀疏数组
 */
public class SparseArray {
    public static void main(String[] args) throws IOException {
        //棋盘大小
        int[][] arr = new int[11][11];

        //棋子布局，1为黑，2为白。
        arr[3][7] = 1;
        arr[2][6] = 2;
        arr[9][6] = 1;
        arr[1][3] = 2;
        arr[10][9] = 1;

        int count = 0;
        System.out.println("原数组为：");
        for (int[] ints : arr) {
            for (int anInt : ints) {
                System.out.printf("%d\t", anInt);
                if (anInt != 0) {
                    count++;
                }
            }
            System.out.println();
        }
        System.out.println();

        //实际数组-->稀疏数组
        int[][] arr2 = new int[count + 1][3];
        arr2[0][0] = arr.length;
        arr2[0][1] = arr[0].length;
        arr2[0][2] = count;

        count = 0;
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                if (arr[i][j] != 0) {
                    count++;
                    arr2[count][0] = i;
                    arr2[count][1] = j;
                    arr2[count][2] = arr[i][j];
                }
            }
        }

        System.out.println("稀疏数组为：");
        for (int[] ints : arr2) {
            for (int anInt : ints) {
                System.out.printf("%d\t", anInt);
            }
            System.out.println();
        }
        System.out.println();

        //稀疏数组-->文件
        System.out.println("开始写出数据");
        OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream("data.txt"));
        StringBuffer buff = new StringBuffer();
        boolean flag = false;
        for (int[] ints : arr2) {
            for (int anInt : ints) {
                if (flag) {
                    buff.append(",").append(anInt);
                } else {
                    buff.append(anInt);
                }
                flag = true;
            }
        }
        out.write(buff.toString());
        out.flush();
        out.close();
        System.out.println("输出数据为-->" + buff);
        System.out.println();

        System.out.println("开始还原数据");
        Scanner s = new Scanner(new FileInputStream("data.txt"));
        s.useDelimiter(",");

        //文件-->稀疏数组
        int[][] arr3 = new int[0][];
        while (s.hasNext()) {
            if (flag) {
                arr3 = new int[s.nextInt()][s.nextInt()];
                s.nextInt();
            } else {
                arr3[s.nextInt()][s.nextInt()] = s.nextInt();
            }
            flag = false;
        }

        //稀疏数组-->原数组
        for (int[] ints : arr2) {
            if (flag) {
                arr3[ints[0]][ints[1]] = ints[2];
            }
            flag = true;
        }

        System.out.println("稀疏数组还原为：");
        for (int[] ints : arr3) {
            for (int anInt : ints) {
                System.out.printf("%d\t", anInt);
            }
            System.out.println();
        }

    }
}

运行结果如下：

原数组为：
0	0	0	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	2	0	0	0	0	
0	0	0	0	0	0	0	1	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	0	0	1	0	0	0	0	
0	0	0	0	0	0	0	0	0	1	0	

稀疏数组为：
11	11	5	
1	3	2	
2	6	2	
3	7	1	
9	6	1	
10	9	1	

开始写出数据
输出数据为-->11,11,5,1,3,2,2,6,2,3,7,1,9,6,1,10,9,1

开始还原数据
稀疏数组还原为：
0	0	0	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	2	0	0	0	0	
0	0	0	0	0	0	0	1	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	0	0	1	0	0	0	0	
0	0	0	0	0	0	0	0	0	1	0