n people came to a party. Then those, who had no friends among people at the party, left. Then those, who had exactly 1 friend among those who stayed, left as w...

Given N integers, you are supposed to find the smallest positive integer that is NOT in the given list.

You want to perform the combo on your opponent in one popular fighting game. The combo is the string ss consisting of nn lowercase Latin letters. To perform the...

You are given the array aa consisting of nn elements and the integer k≤nk≤n.

The organizers of a programming contest have decided to present t-shirts to participants. There are six different t-shirts sizes in this problem: S, M, L, XL, X...

You have array of nn numbers a1,a2,…,ana1,a2,…,an.

You have an array aa of length nn. For every positive integer xx you are going to perform the following operation during the xx-th second:

Today, Yasser and Adel are at the shop buying cupcakes. There are nn cupcake types, arranged from 11 to nn on the shelf, and there are infinitely many of each t...

Among all the factors of a positive integer N, there may exist several consecutive numbers. For example, 630 can be factored as 3×5×6×7, where 5, 6, and 7 are t...

Today, Mezo is playing a game. Zoma, a character in that game, is initially at position x=0x=0. Mezo starts sending nn commands to Zoma. There are two possible ...