Combinatorics Problems

You are given an acyclic, bidirectional graph with NNN nodes and M edges. The nodes are numbered fro...

• By RamprosadG
• Combinatorics, Graph, Tree
• Moderate
• 24/30 Solutions
• 89 Submissions

Milo has a string S of length L. Tutu picks a random prefix and Mota picks a random suffix of S. Now...

• Combinatorics, Counting
• Hard
• 9/19 Solutions
• 29 Submissions

Mr. J wants to learn about combinatorics. He started reading a book on combinatorics and came across...

• By ridowan007
• Combinatorics, Counting, DP
• Moderate
• 96/122 Solutions
• 202 Submissions

There are n people busy with arranging the upcoming Inter Department Programming Contest (IDPC) 2016...

• By Bhadra
• Combinatorics, Counting
• Moderate
• 8/11 Solutions
• 32 Submissions

Let P = C(N,0) - C(N,1) + C(N,2) - C(N,3) + ... + C(N,N); where C(n,r) is "n choose r". Yo...

• By Alim14
• Combinatorics, Counting
• Moderate
• 71/84 Solutions
• 222 Submissions

Mr. Ant has 3 boxes and the infinite number of marbles. Now he wants to know the number of ways he c...

• By Alim14
• Combinatorics, Counting
• Moderate
• 5/14 Solutions
• 23 Submissions

In the strange neighborhood of Nocu, a lot of people lives pretty happily, or so they think. Like mo...

• By TarifEzaz
• Combinatorics, Counting
• Moderate
• 9/16 Solutions
• 35 Submissions

Meera bought candies from the store. She is now going to distribute those among her N friends. She m...

• By forthright48
• Combinatorics, Counting, NumberTheory
• Hard
• 8/41 Solutions
• 194 Submissions

You are at the top left corner[position (1,1)] of a **R X C ** grid. Your destination is bottom righ...

• By Kryptonyte
• Combinatorics, Counting
• Hard
• 10/17 Solutions
• 62 Submissions

As some of you already know, Nocu City has a history of having bad neighbors. These bad ones, take a...

• By TarifEzaz
• Combinatorics, Counting
• Moderate
• 6/7 Solutions
• 78 Submissions

You will be given a set of sequences. Each sequence is a list of numbers. Two sequences are K-simila...

• By ridowan007
• Combinatorics, Counting, DataStructure
• Hard
• 19/27 Solutions
• 302 Submissions

The world is terrified by Pandas! After a miraculous chemical explosion, they became smarter; and ev...

• By mehdi_
• Combinatorics, Counting, NumberTheory
• Hard
• 8/9 Solutions
• 97 Submissions

East West University Computer Programming Club (EWUCoPC) is arranging an Intra-University Programmin...

• Combinatorics
• Hard
• 27/70 Solutions
• 447 Submissions

The problem statement is so small. Give you four integers r, a, b, d. Find the summation of all numb...

• By hasan169
• Combinatorics
• Hard
• 37/113 Solutions
• 668 Submissions

"There was a break-in of Gringotts Wizarding Bank on 1 May, 1998, during the height of the Seco...

• By Sherlock221b
• Bitmask, Combinatorics, Counting, DP
• Hard
• 8/20 Solutions
• 36 Submissions

Imam has been participating in online programming contests for years. His goal is to become a "...

• By TarifEzaz
• Combinatorics, Counting
• Moderate
• 164/202 Solutions
• 585 Submissions

Fear no more, this is a problem of geometry! When Moyna was little, he had a math teacher named Shuk...

• By TarifEzaz
• BruteForce, Combinatorics, Geometry
• Moderate
• 446/555 Solutions
• 1268 Submissions

Alice likes playing with Palindromes (strings that read the same backward as forward, such as 'madam...

• By Sherlock221b
• Combinatorics, Counting
• Hard
• 3/6 Solutions
• 28 Submissions

Little Oishee loves to watch TV. But her mother, who is a math teacher, doesn't like this at all. Sh...

• By IamHot
• Combinatorics, Counting
• Moderate
• 37/50 Solutions
• 174 Submissions

Ever since that wicked thief took away some of her murgis (hens, that is), Meena was ever anxious th...

• By Mesbah
• Combinatorics, DP
• Moderate
• 183/272 Solutions
• 624 Submissions

You are playing a game that has 16 levels. You start with level 1 and after gaining a certain amount...

• By noor148
• Combinatorics
• Moderate
• 18/23 Solutions
• 88 Submissions

Everyone know about Mina & Raju. They are siblings as well as good friend. The friend-circle of ...

• By emrul_mu
• Combinatorics, DP
• Moderate
• 32/44 Solutions
• 169 Submissions

Prof. Bari loves to play with string. He is also very skilled in drawing. One day he was drawing a g...

• Combinatorics
• Hard
• 14/30 Solutions
• 74 Submissions

Mr. Meme has recently moved to a foreign country named "Gloryland" for study purpose. Ther...

• Combinatorics
• Moderate
• 76/100 Solutions
• 233 Submissions

There is an N*N grid where (r,c) denotes a cell number where r means row number, c means column numb...

• By liar_rakib
• Combinatorics
• Hard
• 32/87 Solutions
• 372 Submissions