### khatribiru's blog

By khatribiru, 6 years ago,

Hello Codeforces Community,

I am glad to announce that there will be DEVSKILL CODING CONTEST-22 on 25th May, Friday at 11PM(UTC+6) in Dev Skill. Basically, Dev Skill is a Bangladeshi contest site which arranges two contests every month (one easy contest for beginners and another for everyone ).

This contest will consist of 6 problems and you will be given 2 hours to solve them all.

The score distribution for this contest is: 500 — 700 — 1000 — 1200 — 1500 — 2000

The problems were written and tested by fsshakkhor, bhadra, mahmud2690, BishalG, froghramar, ksohan, mrinmoi, ssavi and me.

We're inviting you all to join us in this contest. Hope you will enjoy solving problems.

Note : Problem's difficulty will be like Codeforces Div3 round

Good luck to all participants!

Ranklist

Congratulations to the winners!!

• +38

By khatribiru, history, 7 years ago,

This blog is just the list of problems for Persistent segment tree. Before start you can learn the topic from here , here & here

Note: Some problem may not need Persistent segment tree but can be solved using this.

Happy New year 2018 to all CF community.

• +75

By khatribiru, history, 8 years ago,

This Blog is Just the List of Problems for Dynamic Programming Optimizations.Before start read This blog.

#### 3. Convex Hull Trick Technique(CHT)

Note:- Some problems from Divide and conquer optimization section can also be solved using CHT.

• +199

By khatribiru, history, 8 years ago,

You are given an array of numbers( N ) (a[i]<= 10^6 && N<= 10^5 ) And 10^5 Queries. In each query You will be given.

X L R.

You have to find the how many numbers are there between L to R such that ( ( a[i] & X )== X ) . Thanks in Advance

• +15

By khatribiru, 9 years ago,

Suppose we are given a array of N numbers. In How many ways we can arrange Numbers ,so that no two same numbers are together. 1<=N<=50 and 1<=array[i]<=16.

• +15