class Solution { public: int findCenter(vector<vector<int>>& edges) { int n=edges.size(); unordered_map<int, int>m; for(int i=0;i<n;i++) { m[edges[i][0]]++; m[edges[i][1]]++; } int ans=0; for(auto x:m) { if(x.second==n) { ans=x.first; break; } } return ans; } };