print a pattern,sorted array

I need help with these problems #1 a function given a integer n will print the following pattern n = 2 222 212 222 n=3 3333 3223 32123 32223 3333

#2 a function that fuind the largest subarray in l , and return these the starting and ending indices with solution in O(n) example l =[1,2,0,1,2,3,0,1,2,3,4,5,-11] returns (6,11)

#3 a function that returns a pair of integers in a list that has a particular sum s. and the solution in O(n) example: l= [5,6,7,1,2] fun(8) returns (6,2)