Java中的稀疏矩阵/数组

public class SparseMatrixCSR {
    private int[] values;
    private int[] columnIndexes;
    private int[] rowPointers;
    private int numRows;
    private int numCols;

    public SparseMatrixCSR(int numRows, int numCols, int[] values, int[] columnIndexes, int[] rowPointers) {
        this.numRows = numRows;
        this.numCols = numCols;
        this.values = values;
        this.columnIndexes = columnIndexes;
        this.rowPointers = rowPointers;
    }

    public int get(int row, int col) {
        int index = findIndex(row, col);
        if (index >= 0) {
            return values[index];
        }
        return 0;
    }

    public void set(int row, int col, int value) {
        int index = findIndex(row, col);
        if (index >= 0) {
            values[index] = value;
        } else {
            // Add new value
            int numValues = values.length;
            int[] newValues = new int[numValues + 1];
            int[] newColumnIndexes = new int[numValues + 1];
            System.arraycopy(values, 0, newValues, 0, numValues);
            System.arraycopy(columnIndexes, 0, newColumnIndexes, 0, numValues);
            newValues[numValues] = value;
            newColumnIndexes[numValues] = col;
            values = newValues;
            columnIndexes = newColumnIndexes;
            rowPointers[row + 1]++;
        }
    }

    private int findIndex(int row, int col) {
        int index = rowPointers[row];
        while (index < rowPointers[row + 1] && columnIndexes[index] < col) {
            index++;
        }
        if (index < rowPointers[row + 1] && columnIndexes[index] == col) {
            return index;
        }
        return -1;
    }
}