lec8_6.cpp

//{ Driver Code Starts
#include <bits/stdc++.h>
using namespace std;


// } Driver Code Ends
class Solution {
  public:
    // Function to detect cycle in an undirected graph.
    
    bool CycleDetect(int node , int parent , vector<vector<int>>& adj , vector<bool>&visited)
    {
        visited[node] =1;
        
        for(int j =0 ;j<adj[node].size();j++)
        {
            if(parent == adj[node][j])
            continue;
            
            if(visited[adj[node][j]])
            return 1;
            
            if(CycleDetect(adj[node][j] , node , adj , visited))
            {
                return 1;
            }
        }
        return 0;
    }
    bool isCycle(vector<vector<int>>& adj) {
        // Code here
        int V = adj.size();
        vector<bool>visited(V , 0);
        
        for(int i = 0 ; i<V; i++)
        {
            if(!visited[i]&& CycleDetect(i , -1 , adj , visited))
            {
                return 1;
            }
        }
        return 0 ;
    }
};

//{ Driver Code Starts.
int main() {
    int tc;
    cin >> tc;
    while (tc--) {
        int V, E;
        cin >> V >> E;
        vector<vector<int>> adj(V);
        for (int i = 0; i < E; i++) {
            int u, v;
            cin >> u >> v;
            adj[u].push_back(v);
            adj[v].push_back(u);
        }
        Solution obj;
        bool ans = obj.isCycle(adj);
        if (ans)
            cout << "1\n";
        else
            cout << "0\n";

        cout << "~"
             << "\n";
    }
    return 0;
}
// } Driver Code Ends