Detect a cycle in Undirected Graph : Breadth-First Search

CPP/Graph/Detect a cycle in Undirected Graph : Breadth-First Search

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+#include <bits/stdc++.h>
+using namespace std;
+class Solution
+{
+public:
+    bool checkForCycle(int s, int V, vector<int> adj[], vector<int> &visited)
+    {
+        // Create a queue for BFS
+        queue<pair<int, int>> q;
+        visited[s] = true;
+        q.push({s, -1});
+        while (!q.empty())
+        {
+            int node = q.front().first;
+            int par = q.front().second;
+            q.pop();
+
+            for (auto it : adj[node])
+            {
+                if (!visited[it])
+                {
+                    visited[it] = true;
+                    q.push({it, node});
+                }
+                else if (par != it)
+                    return true;
+            }
+        }
+        return false;
+    }
+    bool isCycle(int V, vector<int> adj[])
+    {
+        vector<int> vis(V - 1, 0);
+        for (int i = 1; i <= V; i++)
+        {
+            if (!vis[i])
+            {
+                if (checkForCycle(i, V, adj, vis))
+                    return true;
+            }
+        }
+    }
+};
+
+void addEdge(vector<int> adj[],int u,int v)
+{
+    adj[u].push_back(v);
+    adj[v].push_back(u);
+}
+int main()
+{
+    vector<int> adj[5];
+
+    addEdge(adj,0,1);
+    addEdge(adj,0,2);
+    addEdge(adj,2,3);
+    addEdge(adj,1,3);
+    addEdge(adj,2,4);
+
+    Solution obj;
+    int num=obj.isCycle(5, adj);
+    if(num==1)
+    cout<<"Yes"<<endl;
+    else
+    cout<<"No"<<endl;
+
+    return 0;
+    }