's Wiki, local accounts and groups can use it to create ; all of the articles have a hierarchical structure to make the content easy to manage ; can set different for each page or free access to update or lock or release ; users can use a subscription mechanism to get the update ...
此题的标算应该是状压dp,因为按行是严格递增的,所以可以 按列划分阶段,状态存储这一行用了哪些数即可。 其实这题还可以直接套公式。 行和列都严格递增的杨氏矩阵 方案数是 行严格递增列不严格自增,只能填数1-r的方案数是 参考下面的文章 https://en.wikipedia.org/wiki/Young_tableau https://en.wikipedia....