# Find the Town Judge Problem & Solution

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 `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.

## C++ Solution

``````#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops")
#pragma GCC target("avx,avx2,fma")

static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();

class Solution {
public:
int findJudge(int n, vector<vector<int>>& trust) {
vector<int> incoming(n, 0);
vector<int> outgoing(n, 0);
for (int i = 0; i < trust.size(); ++i) {
++incoming[trust[i][1] - 1];
++outgoing[trust[i][0] - 1];
}

for (int i = 0; i < n; ++i) {
if (incoming[i] == n - 1 &&
outgoing[i] == 0) {
return i + 1;
}
}

return -1;
}
};
``````

## Start Here

Many paths, there are. Follow yours, you must.