Critical Connections in a Network LeetCode solution in C++

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class Solution {
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  int timer = 1;
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 public:
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  void dfs(vector<int> adj[], int node, int parent, vector<int> &tin, vector<int> &low,
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           vector<int> &vis, vector<vector<int>> &ans) {
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    vis[node] = 1;
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    tin[node] = low[node] = timer;
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    timer++;
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    for (auto it : adj[node]) {
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      if (it == parent) continue;
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      if (vis[it] == 0) {
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        dfs(adj, it, node, tin, low, vis, ans);
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        low[node] = min(low[node], low[it]);
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        if (tin[node] < low[it]) ans.push_back({node, it});
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      } else {
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        low[node] = min(low[node], low[it]);
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      }
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    }
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  }
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  vector<vector<int>> criticalConnections(int n, vector<vector<int>> &con) {
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    vector<int> adj[n];
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    for (int i = 0; i < con.size(); i++) {
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      adj[con[i][0]].push_back(con[i][1]);
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      adj[con[i][1]].push_back(con[i][0]);
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    }
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    vector<vector<int>> ans;
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    vector<int> vis(n, 0), tin(n, 0), low(n, 0);
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    dfs(adj, 0, -1, tin, low, vis, ans);
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    return ans;
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  }
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};