Independent Column Order Reconciliation

Medium

A reporting pipeline stores two numeric signals in the same table, but downstream ranking requires each signal to be ordered independently before recombining rows. Table: Data first_col: integer metric A second_col: integer metric B the table can contain duplicate rows Task: Produce an output table with the same number of rows as Data such that: first_col is sorted in ascending order. second_col is sorted in descending order. Row i pairs the i-th value from the sorted first_col sequence with the i-th value from the sorted second_col sequence. Output requirements: Return exactly two columns: first_col second_col Return exactly the same number of rows as in Data. Respect the independent ordering rules exactly. Supported submission environments: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

Data:
| first_col | second_col |
|-----------|------------|
| 4         | 2          |
| 2         | 3          |
| 3         | 1          |
| 1         | 4          |

Output

[
  {"first_col":1,"second_col":4},
  {"first_col":2,"second_col":3},
  {"first_col":3,"second_col":2},
  {"first_col":4,"second_col":1}
]

Explanation

Sort first_col ascending -> [1,2,3,4], sort second_col descending -> [4,3,2,1], then pair by index.

Example 2

Input

Data:
| first_col | second_col |
|-----------|------------|
| 5         | 10         |
| 5         | 7          |
| 1         | 7          |
| 3         | 9          |
| 3         | 8          |
| 1         | 10         |

Output

[
  {"first_col":1,"second_col":10},
  {"first_col":1,"second_col":10},
  {"first_col":3,"second_col":9},
  {"first_col":3,"second_col":8},
  {"first_col":5,"second_col":7},
  {"first_col":5,"second_col":7}
]

Explanation

Duplicate values are valid. Column-wise sorting is performed independently before row pairing.

Example 3

Input

Data:
[]

Output

[]

Explanation

No input rows means no output rows.

Constraints

0 <= number of rows in Data <= 900
-1000000000 <= first_col <= 1000000000
-1000000000 <= second_col <= 1000000000
Data may contain duplicate rows
Return exactly two output columns: first_col, second_col
Output row count must equal input row count
Output first_col sequence must be non-decreasing
Output second_col sequence must be non-increasing
For SQL submissions, use SQLite 3.27.2 semantics
For Pandas submissions, return a DataFrame with columns: first_col, second_col

Data: | first_col | second_col | |-----------|------------| | 5 | 10 | | 5 | 7 | | 1 | 7 | | 3 | 9 | | 3 | 8 | | 1 | 10 |

[ {"first_col":1,"second_col":10}, {"first_col":1,"second_col":10}, {"first_col":3,"second_col":9}, {"first_col":3,"second_col":8}, {"first_col":5,"second_col":7}, {"first_col":5,"second_col":7} ]