Educational Codeforces Round 67
CF1187B Letters Shop
Bipartite
https://codeforc.es/contest/1187/submission/56313177
CF1187C Vasya And Array
Direct construction
https://codeforc.es/contest/1187/submission/56316127
CF1187D Subarray Sorting
After these questions, etc. System Test more of it. . .
CF1187E Tree Painting
Directly for root search again
https://codeforces.com/contest/1187/submission/56366512
CF1187F Expected Square Beauty
There \ (n-\) number, each number \ (x_i \) like probability is \ ([l_i, r_i] \ ) of a value.
Set \ (B (x) \) is \ (X \) is equal to the number of consecutive segments
Q \ (E (B (x) ^ 2) \)
Gugu Gu
CF1187G Gang Up
A \ (n-\) points \ (m \) without edges to have a connected graph \ (K \) people who go to \ (1 \) point van♂you♂xi. Each time a person can take a side, you can not go.
If a person had a \ (t \) time only to \ (1 \) dot, to pay \ (c \ cdot t \) price.
If one side while being on a moment in one direction \ (a \) people walking, to pay \ (d \ cdot a ^ 2 \) price.
Seek minimum cost.
Obviously the cost of stratified flow chart. . .
Can be found at most \ (n + k \) time (I think there is sb \ (n \ cdot k \) th to TTTTTTTTTTTTTTTTT)
Direct costs of dismantling the square edge
Stratified direct construction cost flow chart run on the line. . .