Solution -「CCO 2020」Shopping Plans
Desc.Link.有 $N$ 个商品, 每个商品有个种类 $a_i$, 有个价格 $c_i$.对于第 $j$ 个种类, 必须购买个数位于 $[x_j,y_j]$ 的商品, 即最少购买 $x_j...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.