Codeforces Beta Round 24 C. Sequence of points

Codeforces Beta Round 30 (Codeforces format) C. Shooting Gallery

2751. Robot Collisions

There are n 1-indexed robots, each having a position on a line, health, and movement direction.

You are given 0-indexed integer arrays positions, healths, and a string directions (directions[i] is either ‘L’ for left or ‘R’ for right). All integers in positions are unique.

All robots start moving on the line simultaneously at the same speed in their given directions. If two robots ever share the same position while moving, they will collide.

If two robots collide, the robot with lower health is removed from the line, and the health of the other robot decreases by one. The surviving robot continues in the same direction it was going. If both robots have the same health, they are both removed from the line.

Your task is to determine the health of the robots that survive the collisions, in the same order that the robots were given, i.e. final heath of robot 1 (if survived), final health of robot 2 (if survived), and so on. If there are no survivors, return an empty array.

Return an array containing the health of the remaining robots (in the order they were given in the input), after no further collisions can occur.

Note: The positions may be unsorted.

2750. Ways to Split Array Into Good Subarrays

You are given a binary array nums.

A subarray of an array is good if it contains exactly one element with the value 1.

Return an integer denoting the number of ways to split the array nums into good subarrays. As the number may be too large, return it modulo 109 + 7.

A subarray is a contiguous non-empty sequence of elements within an array.

2749. Minimum Operations to Make the Integer Zero

You are given two integers num1 and num2.

In one operation, you can choose integer i in the range [0, 60] and subtract 2i + num2 from num1.

Return the integer denoting the minimum number of operations needed to make num1 equal to 0.

If it is impossible to make num1 equal to 0, return -1.

2748. Number of Beautiful Pairs

You are given a 0-indexed integer array nums. A pair of indices i, j where 0 <= i < j < nums.length is called beautiful if the first digit of nums[i] and the last digit of nums[j] are coprime.

Return the total number of beautiful pairs in nums.

Two integers x and y are coprime if there is no integer greater than 1 that divides both of them. In other words, x and y are coprime if gcd(x, y) == 1, where gcd(x, y) is the greatest common divisor of x and y.

Codeforces Beta Round 33 (Codeforces format) B. String Problem

Codeforces Beta Round 33 (Codeforces format) C. Wonderful Randomized Sum

Codeforces Beta Round 37 B. Computer Game

2747. Count Zero Request Servers

You are given an integer n denoting the total number of servers and a 2D 0-indexed integer array logs, where logs[i] = [server_id, time] denotes that the server with id server_id received a request at time time.

You are also given an integer x and a 0-indexed integer array queries.

Return a 0-indexed integer array arr of length queries.length where arr[i] represents the number of servers that did not receive any requests during the time interval [queries[i] - x, queries[i]].

Note that the time intervals are inclusive.