Codeforces Round #698 Div2 Summary - Construction Problems
All construction problems. The construction problems test the thinking ability and IQ the most. But the problem is that I'm not good at both of it. I'm 蒟蒻.…
Codeforces Round #698 Nezzar and Nice Beatmap - Computational geometry
Solution Let's consider three points first. three point can build a triangle. So at most 1 angle equal or more than $90^\circ$.…
Codeforces Round #698 Nezzar and Binary String - Segment tree
Of course a segment tree problem. Let's start from $f$. Then actually, the state of last day is fixed. Also fixed for the day before last day. The only thing we need to know is how many zeros between $l$ to $r$. Then we can know what is changed.…
Codeforces Round #698 Nezzar and Symmetric Array - Construction
First let's choose any two numbers, $a_i$ and $a_j$. So There must be $-a_i$ and $-a_j$ in $a$. And so there is no need to consider the symbol. Let's assume $a_i>0,\ a_j>0$.…
Codeforces Round #698 Nezzar and Lucky Number - Search by brute force
Let current query is x, let remian=x mod d. If x>=10d}+remain. Then there must be a solution for x.…
Codeforces Round #702 Div3 Solution
Solutions for all problems in Codeforces Round #702 Div3.…
Codeforces Round #708 Div2 Solution
Solutions for C2, D and E2 in Codeforces Round #708 Div2.…
Codeforces Round #708 Square-free division - DP
There is only one case to make product is a perfect square: For each number, the number of occurrences of prime factors is count[i]. if any different $i$, $j$ to make count[i]=count[j].…
