The cycle-chromatic number of a hypergraph H, denoted by c（H）, is defined to be the minimum number of colours needed to colour the vertices of H such that no cycle in H is monochromatic. We proved that, for a hyperg...The cycle-chromatic number of a hypergraph H, denoted by c（H）, is defined to be the minimum number of colours needed to colour the vertices of H such that no cycle in H is monochromatic. We proved that, for a hypergraph H=（V;E1,E2,…, Em） with n vertices, p components, and c（H）= c, we展开更多
它们分别称为Γ_(?) 的第 i 行 ,第 j 列,第 p 条左对角线与第 q 条右对角线.形象地,第 p 条左对角线是从棋盘左下角数起的第 p 条从左上方到右下方的斜线;而第 q 条右对角线是从棋盘左上角数起的第 q 条与左对角线正交的斜线.对Γ_(?)...它们分别称为Γ_(?) 的第 i 行 ,第 j 列,第 p 条左对角线与第 q 条右对角线.形象地,第 p 条左对角线是从棋盘左下角数起的第 p 条从左上方到右下方的斜线;而第 q 条右对角线是从棋盘左上角数起的第 q 条与左对角线正交的斜线.对Γ_(?) 的任一子集 X。展开更多
A generalization of the well-known n-queen problem is to put N×k‘queens’on an k×nchessboard in such a way that each row and each column contains exactly k‘queens’and eachdiagonal with length from 1 to n ...A generalization of the well-known n-queen problem is to put N×k‘queens’on an k×nchessboard in such a way that each row and each column contains exactly k‘queens’and eachdiagonal with length from 1 to n and slope either 1 or -1 contains at most k‘queens’.Aconstruction is given to show that this is always possible whenever n≥4 and n≥k≥1.展开更多
文摘The cycle-chromatic number of a hypergraph H, denoted by c（H）, is defined to be the minimum number of colours needed to colour the vertices of H such that no cycle in H is monochromatic. We proved that, for a hypergraph H=（V;E1,E2,…, Em） with n vertices, p components, and c（H）= c, we
文摘A generalization of the well-known n-queen problem is to put N×k‘queens’on an k×nchessboard in such a way that each row and each column contains exactly k‘queens’and eachdiagonal with length from 1 to n and slope either 1 or -1 contains at most k‘queens’.Aconstruction is given to show that this is always possible whenever n≥4 and n≥k≥1.
