SQL Interview - Puzzle

 Source:

Expected Output:

Query:

Script:

with sample as (

select 1 col1,'a' col2 from dual

union

select 2 col1,'b' col2 from dual

union

select 3 col1,'c' col2 from dual

)

select listagg(t.col2) within group (order by col2) magical_output from sample t

,table (cast (multiset (select level from dual connect by level<=t.col1) as sys.odciNumberList )) lines

group by col2;