nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 1234567891011121314151617181920212223242526272829typedef long long ll;struct cp{ static ll ...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 12345678910111213141516171819202122232425262728293031323334353637383940int top,c[N][2],f[N],tim[N],...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 123456789101112131415161718192021222324252627282930313233343536const int maxn=1e5+5;int to[maxn<...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 霍尔定理推论: 对于一个二分图G<V,E>，若点可以分为两部分N和M,N内部没有边，M同理，S’是N的某个子集(可以为空),f(S’)是与该子集相邻的点集,则他的最大匹配为|N|-m...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 给你两个分数,让你找一个分数在他们俩之间,要求分母最小, 这个问题很显然，我们应该转移到Stern Brocot Tree上面去做,对于给定的两个分数，我们把他们在树上标记出来，可能他们不在树的同一...

先考虑一个简单的问题

$$
f(a,b,c,n)=\sum_{i=0}^n\lfloor\frac{ai+b}{c}\rfloor
$$

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial dp的意义代码中写的很清楚，唯一要注意的是，有一个卡常的地方，显然对于n个点m条边取k个点的斯坦纳树，我们的dp有意义开到dp[1<<k][n]吗？ 这里是不必的，我们只需要开到dp...

nexthexonextbutterflyvolantisyearnyiliashokaindigoapollolandscapecactusmateryicarusfluidmaterial 用最少条数的路径覆盖树，这是一个树dp问题 1234567891011121314151617181920212223void dfs(int u,int father){ in...