$($ALL IN C$++)$Write a function that merges two sorted arrays into one sorted array.

Write a function that finds the majority element in an array $($an element that appears more than n$/2$ times$).$

Write a function that checks if two C$-$style strings are anagrams of each other.

Write a function that rotates an NxN matrix by $90$ degrees in place. Example: Input:

$123$

$456$

$789$

Output:

$741$

$852$

$963$

Write a function that multiplies two matrices and returns the result in a third one provided as a parameter.

The arrays and matrices can be of arbitrary size, which you receive at the start of the program execution.

All input strings can contain white space characters and have a maximum length of $1023$ characters.