在Java中获取子矩阵的参考

在Java中获取子矩阵的参考

我将为

int[][]

数据编写一个包装器，并将其称为Matrix类。然后写一个方法

getSubMatrix(x, y, rows,cols)

。这是一个简单的Matrix类：

static class Matrix {    int[][] data;    int x, y, columns, rows;    public Matrix(int[][] data) {        this(data, 0, 0, data.length, data[0].length);    }    private Matrix(int[][] data, int x, int y, int columns, int rows) {        this.data = data;        this.x = x;        this.y = y;        this.columns = columns;        this.rows = rows;    }    public Matrix getSubMatrix(int x, int y, int columns, int rows) {        return new Matrix(data, this.x + x , this.y + y, columns, rows);    }    public String toString() {        StringBuffer sb = new StringBuffer();        for (int i = y; i < x + rows; i++) { for (int j = x; j < x + columns; j++)     sb.append(data[i][j]).append(" "); sb.append("n");        }        sb.setLength(sb.length() - 1);        return sb.toString();    }}

这个测试程序…：

public static void main(String[] args) throws IOException {    int[][] testData = new int[10][10];    for (int i = 0; i < testData.length; i++)         for (int j = 0; j < testData[i].length; j++) testData[i][j] = 100 + i + j;    Matrix full = new Matrix(testData);    System.out.println("Full test matrix:");    System.out.println(full);    System.out.println();    System.out.println("Part of the matrix:");    System.out.println(full.getSubMatrix(3, 3, 3, 3));}

…打印：

Full test matrix:100 101 102 103 104 105 106 107 108 109 101 102 103 104 105 106 107 108 109 110 102 103 104 105 106 107 108 109 110 111 103 104 105 106 107 108 109 110 111 112 104 105 106 107 108 109 110 111 112 113 105 106 107 108 109 110 111 112 113 114 106 107 108 109 110 111 112 113 114 115 107 108 109 110 111 112 113 114 115 116 108 109 110 111 112 113 114 115 116 117 109 110 111 112 113 114 115 116 117 118Part of the matrix:106 107 108 107 108 109 108 109 110