Suppose we have two numbers n and k. We are determined to rearrange natural numbers. But there are too many natural numbers, so we have decided to start with the first n. Pick the following sequence of numbers: firstly, all odd integers from 1 to n (in ascending order), then ... Read More

Suppose we have a string S with n characters. In a joke programming language, there are only 4 instructions."H" to print "Hello World""Q" to print its source code"9" to print "99 bottles of juice""+" to increment the value stored in accumulatorInstructions "H" and "Q" are case-sensitive and they must be ... Read More

Suppose we have a binary string S of size n. Amal loves football very much. One day, he was watching a match, he was writing the players' current positions on a piece of paper. The given string is the written position. A zero corresponds to players of one team; a ... Read More

Suppose we have a string S with n characters. As it's the first of April, Amal is suspecting that the news she reads today are fake, and he does not want to look silly in front of all the contestants. He knows that a news is fake if it contains ... Read More

Suppose we have a number n. We are developing a project to build a new data center. The plot of this data center will be a rectangle with an area of exactly n square meters. Each side of the data center must be an integer. We want to minimize the ... Read More

Suppose we have an array A with four lines. Amal wants to draw four line segments on a sheet of paper. The i-th segment to have its length equal to A[i]. These segments can intersect with each other, and each segment should be either horizontal or vertical. Amal wants to ... Read More

Suppose we have a string S with brackets. There are two types of brackets '(' ')' and '[', ']'. A string is called a regular bracket sequence (RBS) if it follows following types −empty string;'(' | RBS | ')';'[' | RBS | ']';RBS | RBS.Where '|' is a concatenation of ... Read More

Suppose we have two string S and T, and another string R. There are two popular keyboard layouts represented in S and T, they differ only in letters positions. All the other keys are the same. In S and T, all keys of the first and the second layouts in ... Read More

Suppose we have two numbers h and w. The height and width of a table. The table is divided into h × w cells. Into each cell of the table, we can either put a plate or keep it empty. As each guest has to be seated next to their ... Read More

Suppose we have a binary string S with n bits. Let an operation MEX of a binary string be the smallest digit among 0, 1, or 2 that does not occur in the string. For example, MEX(001011) is 2, because 0 and 1 occur in the string at least once, ... Read More