Find Players With Zero or One Losses

arrayhash tablesorting

Problem Statement

You are given an integer array matches where matches[i] = [winner _i , loser _i ] indicates that the player winner _i defeated player loser _i in a match.

Return a list answer of size 2 where:

answer[0] is a list of all players that have not lost any matches.

answer[1] is a list of all players that have lost exactly one match.

The values in the two lists should be returned in increasing order.

Note:

You should only consider the players that have played at least one match.

The testcases will be generated such that no two matches will have the same outcome.

Examples

Example 1

Input: matches = [[1,3],[2,3],[3,6],[5,6],[5,7],[4,5],[4,8],[4,9],[10,4],[10,9]]
Output: [[1,2,10],[4,5,7,8]]
Players 1, 2, and 10 have not lost any matches.
Players 4, 5, 7, and 8 each have lost one match.
Players 3, 6, and 9 each have lost two matches.
Thus, answer[0] = [1,2,10] and answer[1] = [4,5,7,8].

Example 2

Input: matches = [[2,3],[1,3],[5,4],[6,4]]
Output: [[1,2,5,6],[]]
Players 1, 2, 5, and 6 have not lost any matches.
Players 3 and 4 each have lost two matches.
Thus, answer[0] = [1,2,5,6] and answer[1] = [].

Constraints

1 <= matches.length <= 10 ^5

matches[i].length == 2

1 <= winner _i , loser _i <= 10 ^5

winner _i != loser _i

All matches[i] are unique .

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table