851

class Solution {
public:
    vector<int> loudAndRich(vector<vector<int>>& richer, vector<int>& quiet) {
        int n = quiet.size();
        vector<vector<int>> graph(n);

        for(auto edge: richer)
            graph[edge[1]].push_back(edge[0]);

        vector<int> ans(n, -1);
        for(int i=0; i<n; i++){
            if(ans[i] == -1)
                dfs(i, graph, quiet, ans);
        }
        return ans;
    }

    int dfs(int node, vector<vector<int>> &graph, vector<int>& quiet, vector<int> &ans){
        if(ans[node] != -1) return (quiet[ans[node]] < quiet[node]) ? ans[node] : node;
        int res = node;
        for(auto child: graph[node]){
            int subtreeSmall = dfs(child, graph, quiet, ans);
            if(quiet[res] > quiet[subtreeSmall])
                res = subtreeSmall;
        }
        return ans[node] = res;
    }

};