Players With Zero or One Losses

Each item of matches is [winner, loser] for one game. Return a list of two lists:

• players who played and never lost, and
• players who lost exactly once,

each sorted in increasing order. Only count players who appear in at least one match.

Example 1

Input: matches = [[3, 1], [2, 1], [3, 4], [5, 2]]
Output: [[3, 5], [2, 4]]

1 lost twice; 2 and 4 lost once; 3 and 5 never lost.

Example 2

Input: matches = [[1, 2]]
Output: [[1], [2]]

Example 3

Input: matches = [[4, 7], [7, 4], [4, 7]]
Output: [[], [4]]

Constraints

• 1 ≤ matches.length ≤ 10⁵
• 1 ≤ player ids ≤ 10⁶
• A player never plays themselves.