I think there is no official post by rng_58 for abc 129, so lets discuss problem here.

Any approaches for problem F, Takahashi's Basics in Education and Learning.

hello, how to solve problem f of today's abc 126 ? https://atcoder.jp/contests/abc126/tasks/abc126_f . since editorial is in japanese.

i also request rng_58 to add english version of editorial , since the rating has been increased to 1999.

I Just look at editorials even looks much harder than gcj finals and i was like ..ITS IMO.

In Problem 877F , how to apply Mo's algorithm ? while traversing each block what to do ? editorial is not well explained .

Suppose a[] = { 1 , 1 , 1 , -1 } . We want to get all subarray's in the range 2--4 with sum = 1 .

Approach with HashMap would be linear complexity and total Time Complexity would be O(N*Q) if there are q queries.

**how to reduce it to sqrt. decomposition . **