c++ - N维网格顶点计算

Question

问题：给定一个单元格索引（红色）计算围绕单元格索引的数组索引（黑色）。

bool CalculateCellVerticesFromIndex(size_t index, size_t* vertices)
{
    size_t gridSize[2] = {6, 5};
    return true;  // if the index was valid
    return false; // if the index was invalid
}

计算在已知大小 (m X n X ... ) 的 N 维网格中围绕单元格的顶点。

示例图：

说int vertices[4] = {0, 0, 0, 0}

上图中，CalculateCellVerticesFromIndex(12, vertices); 应该用 {14, 15, 20, 21} 填充顶点；

Answer 1

Width = 6
Row = Index div (Width - 1)
if Row > 5 - 2 then OutOfGrid
Column = Index mod (Width - 1)
LeftBottom = Row * Width + Column
LeftTop = LeftBottom + Width
RightBottom and RightTop - elaborate