diff --git a/Cycle Detection in undirected graphs using BFS b/Cycle Detection in undirected graphs using BFS
new file mode 100644
index 00000000..9f0c46d3
--- /dev/null
+++ b/Cycle Detection in undirected graphs using BFS	
@@ -0,0 +1,101 @@
+#include<unordered_map>
+#include<queue>
+#include<list>
+
+bool isCyclicBFS(int src,unordered_map<int, bool>&visited,
+unorderd_map<int, list<int> >&adj, unordered_map<int,int> parent) 
+{
+	parent[src] = -1;
+	visited[src] = 1;
+	queue<int> q;
+	q.push(src);
+	
+	while(!q.empty) {
+		int front = q.front();
+		q.pop();
+		
+		for(auto neighbour: adj[front]) {
+			if(visited[neighbour] == true && neighbour != parent[front]) 
+			{
+				return true;
+			}
+			else if(!visited[neigbour]) 
+			{
+				q.push(neighbour);
+				visited[neibhour] = 1;
+				parent[neighbour] = front;
+			}
+		}
+	}
+	return false;
+}
+
+
+
+string cycleDetection (vector<vector<int>& edges, int n, int m) {
+	//create adjacency list
+	unorderd_map<int, list<int> >adj;
+	for(int i=0; i<m; i++) {
+		int u = edges[i][0];
+		int v = edges[i][1];
+		
+		adj[u].push_back(v);
+		adj[v].push_back(u);
+	}
+	
+	//to handle disconnected components
+	for( int i=0; i<n; i++) {
+		if(!visited[i]) 
+		{
+			bool ans = isCyclicBFS(i, visited, adj);
+			if(ans == 1)
+			return "Yes";
+		}
+	}
+	return "No";
+}
+//t.c: linear
+
+//Cycle Detection in undirected graphs using DFS...
+
+bool isCyclicDFS(int node, int parent, unordered_map<int,bool>&visited,
+unoredered_map<int, list<int> >&adj){
+	visited[node] = true;
+	
+	for(auto neighbour: adj[node]) {
+		if(!visited[neighbour]) {
+		
+		bool cycleDetected = isCyclicDFS(neihbour, node, visited, adj);//rec call
+		if(cycleDetected) 
+		return true;
+	}
+	else if(neighbour!=parent) {
+		//cycle present
+		return true;
+	}
+}
+return false;
+}
+
+
+string cycleDetection (vector<vector<int>& edges, int n, int m) {
+	//create adjacency list
+	unorderd_map<int, list<int> >adj;
+	for(int i=0; i<m; i++) {
+		int u = edges[i][0];
+		int v = edges[i][1];
+		
+		adj[u].push_back(v);
+		adj[v].push_back(u);
+	}
+	
+	//to handle disconnected components
+	for( int i=0; i<n; i++) {
+		if(!visited[i]) 
+		{
+			bool ans = isCyclicDFS(i, -1, visited, adj);
+			if(ans == 1)
+			return "Yes";
+		}
+	}
+	return "No";