Ryan Lie

// the code probably needs more bounds checking

abstract class Slice extends AbstractList {
  Object[][] table;
  Slice(Object[][] table) {
    this.table = table;
  }
  Object get(int row, int col) {
    return this.table[row][col];
  }
  Object set(int row, int col, Object element) {
    Object prev = this.table[row][col];
    this.table[row][col] = element;
    return prev;
  }
}

class RowSlice extends Slice {
  private int row;
  RowSlice(Object[][] table, int row) {
    super(table);
    this.row = row;
  }

  int size() {
    return this.table[row].length;
  }

  Object get(int col) {
    return super.get(row, col);
  }
  Object set(int col, Object element) {
    return super.set(row, col, element);
  }
}

class ColumnSlice extends Slice {
  private int col;
  ColumnSlice(Object[][] table, int col) {
    super(table);
    this.col = col;
  }
  int size() {
    return this.table.length;
  }
  Object get(int row) {
    return super.get(row, col);
  }
  Object set(int row, Object element) {
    return super.set(row, col, element);
  }
}

// note: we cannot use primitive type since int is not
// a type of Object; i.e. boxed type only
Integer[][] newTwoDim = new Integer[][] {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}};

Slice rowOne = new RowSlice(newTwoDim, 1);
Slice colOne = new ColumnSlice(newTwoDim, 1);
Slice[] slices = new Slice[] {rowOne, colOne};

// note that because we inherits from AbstractList, there is
// already a toString() implementation from AbstractList:
print(rowOne); // [5, 6, 7, 8]
print(colOne); // [2, 6, 10]

for (int i = 0; i < slices.length; i++) {
  Slice flat = slices[i];
  for (int j = 0; j < flat.size(); j++) {
    int n = (Integer) flat.get(j);
    flat.set(j, n + 1);
  }
}

print(rowOne); // [6, 8, 8, 9]
print(colOne); // [3, 8, 11]