给定 4 列 x 8 行:

Given 4 columns by 8 rows then:

i = row * 4 + col

我的错，显然没有人发现我犯了这个错误.但它实际上应该是 row * 4 + col.

My bad, nobody caught me on this mistake apparently. But it should actually be row * 4 + col.

row * 8 + col 会在可能的索引中留下不必要的间隙.

row * 8 + col would leave unnecessary gaps in the possible indexes.