Comet OJ 2019 summer season joy solution to a problem
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A complete binary tree k
\ (n-\) diameter tree completely k th point.
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B from the United States
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C toast
\(n!!!\mod p\)
Obviously \ (n \) too is 0, or direct violence
D tea Yan Yue color
The original title
E Ludo
The last is certainly the starting point -> The last \ (k \) points -> end (spring back -> ..-> spring back -> ..-> end)
Take the starting point to the last moment to make a \ (k \) probability points \ (f_i \) and the desired number of steps \ (G_i \) .
Finally \ (K \) point to an end point of any desired number of steps must be \ (K \) , so the answer is \ (\ NK sum_ {I} = ^ {}. 1-n-f_ik G_i + \) .
F triples
\ (2 \ min (a_i + a_j, bi + b_j) \ leq \ max (a_i + a_j, b_i + b_j) \) according to the size relation of two meanings. Eliminate \ (\ min, max \ \ ) were forwarded to the two-dimensional partial ordering problem after the shift.
G school basketball tournament
I like to sing ♂ ♂ basketball jump ♂rap♂
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H assigned student number
From small to large merger. Suppose \ (A \) individual student number \ (\ GEQ P \) , \ (B \) individual student number \ (\ GEQ Q \) , \ (P <Q \)
If \ (A \ Leq QP \) , then multiply the answer \ (A! \) , Throw away \ (A \) .
Otherwise, the answer by \ (C_ {A} ^ {QP} \) , \ (= A- B + (QP) \) , throw \ (A \) .
I Gree heart
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