(n: int)
return I
Returns the Identity matrix of size n x n
    Time Complexity: O(n^2)
Returns the Identity matrix of size n x n
    Time Complexity: O(n^2)
Returns the Identity matrix of size n x n Time Complexity : O ( n^2 )
def identity(n: int) -> list:
    """
    Returns the Identity matrix of size n x n
    Time Complexity: O(n^2)
    """
    I = [[0 for i in range(n)] for j in range(n)]
    
    for i in range(n):
        I[i][i] = 1
    
    return I
def identity ( n : int ) -> list : I = [ [ 0 for i in range ( n ) ] for j in range ( n ) ] for i in range ( n ) : I [ i ] [ i ] = 1 return I