You are given an m x n matrix ‘mat’ and an integer ‘k’. The rows of the matrix undergo cyclic shifts: even-indexed rows shift left, and odd-indexed rows shift right. After performing these k shifts, determine if the matrix is identical to its original form.
You are given a list called mountain, which contains integers. Your task is to find all the indices that represent peaks in the list. A peak is defined as an element that is strictly greater than its immediate left and right neighbors. The first and last elements of the list cannot be peaks. Return a list of indices that correspond to the peaks in the mountain array.
You are given two integer arrays, nums1 and nums2, with sizes n and m respectively. Your task is to find the number of indices i such that nums1[i] exists in nums2 and the number of indices i such that nums2[i] exists in nums1. Return both values as an array [answer1, answer2].
You are given an integer array batteryPercentages representing the battery levels of devices. Perform tests on each device in order, testing a device if its battery percentage is greater than 0 and decrementing the battery percentage of all subsequent devices by 1. Return the number of devices that can be tested after performing the operations.
You are given a 2D integer matrix grid of size n * n. The matrix contains integers in the range [1, n²], and each number appears exactly once, except for two numbers. One number a is repeated twice, and another number b is missing. Find the repeating and missing numbers a and b.
You are given an array nums containing positive integers. Your task is to find the total frequency of the elements in nums that appear the maximum number of times. The frequency of an element is defined as the number of times that element occurs in the array. You need to return the sum of frequencies of all elements that have the maximum frequency.