997 - Find the Town Judge\.

Easy

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 <code>trusti = a_i, b_i</code> representing that the person labeled <code>a_i</code> trusts the person labeled <code>b_i</code>. If a trust relationship does not exist in trust array, then such a trust relationship does not exist.

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

• <code>0 <= trust.length <= 10⁴</code>

• trust[i].length == 2

• All the pairs of trust are unique.

• <code>a_i != b_i</code>

• <code>1 <= a_i, b_i<= n</code>