Friends

#include <bits/stdc++.h>
using namespace std;

const int N = 505;
vector<int> edges[N];
int n;
int vis[N];

int dfs(int root) {
    vis[root] = 1;
    set<int> s;
    for (auto &child : edges[root]) {
        s.insert(child);
    }

    /*
        Here we just check that if the child of a child
        is from the set of children of the root, if so that means
        This is a cycle. You can simply get the score of this trio
        By removing 2*3 edges(due to trio members)
    */
    int ans = INT_MAX;
    for (auto &child : edges[root]) {
        for (auto &cchild : edges[child]) {
            if (s.find(cchild) != s.end()) {
                int cnt = edges[root].size() + edges[child].size() + edges[cchild].size() - 6;
                ans = min(ans, cnt);
            }
        }
    }

    return ans;
}

int bestTrio(int friends_node, vector<int> friends_from, vector<int> friends_to) {
    n  = friends_node;
    for (int i = 0; i < N; ++i) {
        edges[i].clear();
    }
    memset(vis, -1, sizeof(vis));
    for (int i = 0; i < friends_from.size(); ++i) {
        edges[friends_from[i]].push_back(friends_to[i]);
        edges[friends_to[i]].push_back(friends_from[i]);
    }

    int ans = INT_MAX;
    for (int i = 0; i < n; ++i) {
        if (!vis[i]) {
            ans = min(ans, dfs(i));
        }
    }


    return ans;
}