Find the Town Judge

Problem statement

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:

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 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

My solution

/**
 * @param {number} n
 * @param {number[][]} trust
 * @return {number}
 */
var findJudge = function(n, trust) {
    if (!trust.length && n === 1) {
        return 1
    }
    
    let maxFreq = Number.MIN_SAFE_INTEGER;
    const trustFreq = new Map();
    
    for (const [truster, trustee] of trust) {
        if (!trustFreq.has(trustee)) {
            trustFreq.set(trustee, 0)
        }
        
        trustFreq.set(trustee, trustFreq.get(trustee) + 1)
        
        maxFreq = Math.max(maxFreq, trustFreq.get(trustee));
        
        // console.log("maxFreq", maxFreq)
    }
    
    // console.log(trustFreq, maxFreq)
    
    const trustBank = new Map(trust);
    for (let i = 1; i <= n; i++) {
        // console.log(i, trustBank, trustBank.has(i), maxFreq)
        if (!trustBank.has(i) && maxFreq === n - 1) {
            return i
        }
    }
    
    return -1
};