Merge pull request #881 from Karnika06/Devincept15

Added Bridge edge in Graph problem

Author: smv1999

Codechef Problems/MaximumArrayXOR.java

@@ -0,0 +1,123 @@
+/*
+Implementation of Bridge edge in Graph problem
+
+Problem statement: 
+Given an undirected graph of V vertices and E edges and another edge (c-d), the task is to 
+find if the given edge is a bridge in graph, i.e., removing the edge disconnects the graph.
+
+Link to the problem: https://practice.geeksforgeeks.org/problems/bridge-edge-in-graph/1
+
+*/
+
+#include<bits/stdc++.h>
+using namespace std;
+
+
+class Solution
+{
+	public:
+
+    void dfs( vector<int> adj[],vector<int>&v,int i)
+    {
+        //marking visited
+        v[i]=1; 
+
+        //traversing adjacent node
+        for(auto x:adj[i]) 
+        {
+            if(!v[x])
+                dfs(adj,v,x);
+
+        }
+
+    }
+
+    bool connected(vector<int>adj[],int n,int c,int d)
+    {
+        vector<int>v(n,0);
+
+        // dfs from edge c
+        dfs(adj,v,c); 
+
+        //if edge d is not visited means not connected
+        if(v[d]==0) 
+            return false;
+
+        return true;
+
+    }
+
+    //Function to find if the given edge is a bridge in graph.
+    int isBridge(int n, vector<int>adj[], int c, int d) 
+    {
+        //if graph is not connected
+        if(!connected(adj,n,c,d)) 
+            return 0;
+
+        else
+        {
+            //removing edge c and d
+            adj[c].erase(remove(adj[c].begin(), adj[c].end(), d), adj[c].end());
+            adj[d].erase(remove(adj[d].begin(), adj[d].end(), c), adj[d].end());
+
+            //if connected means no bridge
+            if(connected(adj,n,c,d)) 
+                return 0;
+            else
+                return 1;
+        }
+
+    }
+};
+
+// Driver Code Starts
+int main()
+{
+    int t;
+    cin >> t;
+    while (t--) 
+    {
+        int V, E;
+        cin >> V >> E;
+        vector<int> adj[V];
+        int i=0;
+        while (i++<E) 
+        {
+            int u, v;
+            cin >> u >> v;
+            adj[u].push_back (v);
+            adj[v].push_back (u);
+        }
+
+        int c,d;
+        cin>>c>>d;
+
+        Solution obj;
+    	cout << obj.isBridge(V, adj, c, d) << "\n";
+    }
+
+    return 0;
+}
+
+
+/*
+Time Complexity : O(V+E)
+Space Complexity : O(V)
+
+Input:
+t=1
+V=4 E=3
+0 1
+1 2
+2 3
+c=1  d=2
+
+Output: 1
+
+Explanation:
+From the graph, we can clearly see that
+removing the edge 1-2 will result in 
+disconnection of the graph. So, it is 
+a bridge Edge and thus the Output 1.
+
+*/