Write a function that takes an integer n as a parameter, and computes an n × n grid (list of lists) called H in which all cells on the main diagonal contain a 1 and the rest of the cells contain a 0. For example, if n = 5, your function should compute the grid

[[1, 0, 0, 0, 0],
[0, 1, 0, 0, 0],
[0, 0, 1, 0, 0],
[0, 0, 0, 1, 0],
[0, 0, 0, 0, 1]]