一个快速且灵活的通用稀疏二维数组。

特点

  • 公开图形，以便客户端可以轻松地在相邻元素之间直接遍历，从而实现快速的数组遍历。
  • 密集格式和稀疏格式之间的轻松转换。

用法

示例

final sparse = SparseArray2D<String>();

sparse.put(2, 0, 'a');
sparse.put(2, 1, 'b');
sparse.put(2, 5, 'c');
sparse.put(2, 8, 'd');
sparse.put(0, 5, 'e');

print('Sparse form elements');
print(sparse.rows.join('\n'));

print('Dense form values');
print(sparse.denseRows.join('\n'));

print('Dense form with default value "_"');
print(sparse.denseRows.map((final row) => row.padded('-')).join('\n'));

print('Extract row as sparse elements');
print(sparse.rowAt(2));

print('Extract row as sparse values with default value "*"');
print(sparse.rowAt(2)!.dense.padded('*'));

print('Extract column as sparse elements');
print(sparse.columnAt(5)!.join('\n'));

print('Extract column as sparse values with default value "*"');
print(sparse.columnAt(5)!.dense.padded('*').join('\n'));

输出

Sparse form elements
(0)[(0, 5)[e]]
(2)[(2, 0)[a],(2, 1)[b],(2, 5)[c],(2, 8)[d]]

Dense form values
(null, null, null, null, null, e, null, null, null)
(null, null, null, null, null, null, null, null, null)
(a, b, null, null, null, c, null, null, d)

Dense form with default value "_"
(-, -, -, -, -, e, -, -, -)
(-, -, -, -, -, -, -, -, -)
(a, b, -, -, -, c, -, -, d)

Extract row as sparse elements
(2)[(2, 0)[a],(2, 1)[b],(2, 5)[c],(2, 8)[d]]

Extract row as sparse values with default value "*"
(a, b, *, *, *, c, *, *, d)

Extract column as sparse elements
(0, 5)[e]
(2, 5)[c]

Extract column as sparse values with default value "*"
e
*
c

GitHub

查看 Github