--simon:
博客地址：https://www.cnblogs.com/--simon/
--simon:
博客地址：https://www.cnblogs.com/--simon/
Codeforces Round #589 (Div. 2)-E. Another Filling the Grid-容斥定理
Educational Codeforces Round 72 (Rated for Div. 2)-D. Coloring Edges-拓扑排序
Codeforces Round #581 (Div. 2)-E. Natasha, Sasha and the Prefix Sums-动态规划+组合数学
Manthan, Codefest 19 (open for everyone, rated, Div. 1 + Div. 2)-C. Magic Grid-构造