In a town, there are n
people labeled from 1
to n
. There is a rumor that one of these people is secretly the town judge.
If the town judge exists, then:
- The town judge trusts nobody.
- Everybody (except for the town judge) trusts the town judge.
- There is exactly one person that satisfies properties 1 and 2.
You are given an array trust
where trust[i] = [ai, bi]
representing that the person labeled ai
trusts the person labeled bi
.
Return the label of the town judge if the town judge exists and can be identified, or return -1
otherwise.
Example 1:
Input: n = 2, trust = [[1,2]] Output: 2
Example 2:
Input: n = 3, trust = [[1,3],[2,3]] Output: 3
Example 3:
Input: n = 3, trust = [[1,3],[2,3],[3,1]] Output: -1
Constraints:
1 <= n <= 1000
0 <= trust.length <= 104
trust[i].length == 2
- All the pairs of
trust
are unique. ai != bi
1 <= ai, bi <= n