Leetcode online Find the judge, graph with highest degree
This is a wonderfully succinct solution. I will make one point:

final int[] degreeArray = new int[N + 1];


This creates a never-used int at degreeArray[0]. I understand that this was a choice so as to be able to use a simple access by value of the trustees:

degreeArray[itemInTrustArray[0]]--;


In the interest of creating the minimum number of objects necessary, and thus using the least memory possible, I would recommend initializing degreeArray to length N

final int[] degreeArray = new int[N];


And then left shifting your insert by value statements

degreeArray[itemInTrustArray[0]--]--;
degreeArray[itemInTrustArray[1]--]++;


and finally updating your final for loop to account for this change to the zero-based indexing inherent to arrays

// Now iterate though the degreeArray to find the index having degree as N-1.
for (int i = 0; i &lt; N; i++) {


Since you are working with int primitives, the math operators here would add only a near-vanishing amount to overall runtime, if that is a concern.