js sol
/**
* @param {number} n
* @param {number[][]} trust
* @return {number}
*/
var findJudge = function(n, trust) {
// If only the judge exists return the judge
if (!trust.length && n === 1) return n
// find the number everyone trusts
// and find the number that trusts nobody
// if the numbers of the two conditions above exists and are equal
// and the there is no trust[i][0] that matches the value of the statements above
// return the number else return -1
let maxTrustFreq = -Infinity, trustFreq = new Map()
for (const [truster, trustee] of trust) {
if (!trustFreq.has(trustee)) {
trustFreq.set(trustee, 1)
} else {
trustFreq.set(trustee, trustFreq.get(trustee) + 1)
}
// Find running max trust value
const freq = trustFreq.get(trustee)
if (freq > maxTrustFreq) {
maxTrustFreq = freq
}
}
const trustBank = new Map(trust)
for (let i = 1; i <= n; i++) {
if (!trustBank.has(i) && maxTrustFreq === n - 1) return i
}
return -1
};
Zealous Zebra