2896. Apply Operations to Make Two Strings Equal

You are given two 0-indexed binary strings s1 and s2, both of length n, and a positive integer x.

You can perform any of the following operations on the string s1 any number of times:

• Choose two indices i and j, and flip both s1[i] and s1[j]. The cost of this operation is x.
• Choose an index i such that i < n - 1 and flip both s1[i] and s1[i + 1]. The cost of this operation is 1.

Return the minimum cost needed to make the strings s1 and s2 equal, or return -1 if it is impossible.

Note that flipping a character means changing it from 0 to 1 or vice-versa.

2895. Minimum Processing Time

You have n processors each having 4 cores and n * 4 tasks that need to be executed such that each core should perform only one task.

Given a 0-indexed integer array processorTime representing the time at which each processor becomes available for the first time and a 0-indexed integer array tasks representing the time it takes to execute each task, return the minimum time when all of the tasks have been executed by the processors.

Note: Each core executes the task independently of the others.

2894. Divisible and Non-divisible Sums Difference

You are given positive integers n and m.

Define two integers, num1 and num2, as follows:

• num1: The sum of all integers in the range [1, n] that are not divisible by m.
• num2: The sum of all integers in the range [1, n] that are divisible by m.

Return the integer num1 - num2.

Problem D: Today is Gonna be a Great Day

Problem C1: Back in Black (Chapter 1)

Problem B2: Sum 41 (Chapter 2)

Problem B1: Sum 41 (Chapter 1)

Problem A: Here Comes Santa Claus

Inverted cells

The maximum number