Leetcode 997. Find the Town Judge

In a town, there are N people labelled from 1 to N.  There is a rumor that one of these people is secretly the town judge.

If the town judge exists, then:

1. The town judge trusts nobody.
2. Everybody (except for the town judge) trusts the town judge.
3. There is exactly one person that satisfies properties 1 and 2.

You are given trust, an array of pairs trust[i] = [a, b] representing that the person labelled a trusts the person labelled b.

If the town judge exists and can be identified, return the label of the town judge.  Otherwise, return -1.

 

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

Example 4:

Input: N = 3, trust = [[1,2],[2,3]]
Output: -1

Example 5:

Input: N = 4, trust = [[1,3],[1,4],[2,3],[2,4],[4,3]]
Output: 3

 

Note:

1. 1 <= N <= 1000
2. trust.length <= 10000
3. trust[i] are all different
4. trust[i][0] != trust[i][1]
5. 1 <= trust[i][0], trust[i][1] <= N

public int findJudge(int N, int[][] trust) {
        label: for (int i = 1; i <= N; i++) {
            boolean out = true;
            boolean beTrusted = false;
            for (int[] arr : trust) {
                if (arr[0] == i) {
                    out &= false;
                    continue label;
                } else {
                    out &= true;
                }
            }
            if (out) {
                int count = 0;
                for (int[] arr : trust) {
                    if (arr[1] == i) {
                        count++;
                    }
                }
                if (count+1 == N) return i;
            }
        }
        return -1;
    }