A parentheses string is valid if and only if:
Given a string s, remove the vowels 'a', 'e', 'i', 'o', and 'u' from it, and return the new string.
There are n buildings in a line. You are given an integer array heights of size n that represents the heights of the buildings in the line.
Given a 2D matrix matrix, handle multiple queries of the following type:Calculate the sum of the elements of matrix inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2).
Given a 2D integer array matrix, return the transpose of matrix.