Amr and Music
Amr is a young coder who likes music a lot. He always wanted to learn how to play music but he was busy coding so […]
Month: May 2020
Amr and Pins
Amr loves Geometry. One day he came up with a very interesting problem. Amr has a circle of radius r and center in point (x, y). He wants the […]
Guess Your Way Out!
Amr bought a new video game “Guess Your Way Out!”. The goal of the game is to find an exit from the maze that looks […]
Breaking Good
Breaking Good is a new video game which a lot of gamers want to have. There is a certain level in the game that is […]
The Maths Lecture
Amr doesn’t like Maths as he finds it really boring, so he usually sleeps in Maths lectures. But one day the teacher suspected that Amr […]
Fox And Jumping
Fox Ciel is playing a game. In this game there is an infinite long tape with cells indexed by integers (positive, negative and zero). At […]
Fox And Names
Fox Ciel is going to publish a paper on FOCS (Foxes Operated Computer Systems, pronounce: “Fox”). She heard a rumor: the authors list on the […]
Fox And Travelling
Fox Ciel is going to travel to New Foxland during this summer. New Foxland has n attractions that are linked by m undirected roads. Two attractions are called adjacent […]
Fox And Dinner
Fox Ciel is participating in a party in Prime Kingdom. There are n foxes there (include Fox Ciel). The i-th fox is a i years old. They will have dinner […]
Fox And Polygon
Fox Ciel just designed a puzzle game called “Polygon”! It is played using triangulations of a regular n-edge polygon. The goal is to transform one triangulation to another […]
Second price auction
Nowadays, most of the internet advertisements are not statically linked to a web page. Instead, what will be shown to the person opening a web […]
Permutations
You are given a permutation p of numbers 1, 2, …, n. Let’s define f(p) as the following sum: Find the lexicographically m-th permutation of length n in the set of permutations having the maximum possible […]
Constrained Tree
You need to find a binary tree of size n that satisfies a given set of c constraints. Suppose that the nodes of the unknown binary tree are labeled […]
Subarray Cuts
You are given an array of length n and a number k. Let’s pick k non-overlapping non-empty subarrays of the initial array. Let s i be the sum of the i-th subarray in order […]
Scaygerboss
Cthulhu decided to catch Scaygerboss. Scaygerboss found it out and is trying to hide in a pack of his scaygers. Each scayger except Scaygerboss is […]
Inversions problem
You are given a permutation of n numbers p 1, p 2, …, p n. We perform k operations of the following type: choose uniformly at random two indices l and r ( l ≤ r) and reverse the order of the elements p l, p l + 1, …, p r. […]
Photo to Remember
One day n friends met at a party, they hadn’t seen each other for a long time and so they decided to make a group photo together. […]
Chicken or Fish?
Polycarp is flying in the airplane. Finally, it is his favorite time — the lunchtime. The BerAvia company stewardess is giving food consecutively to all the […]
