program to check undirected graph is bipartite or not in c++

code/graph_algorithms/src/Bipartite_check/bipartite.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include <vector>
+#include <queue>
+int main()
+{
+    long int vertex , edge , u , v , counter ;
+    bool flag = false;
+    // taking n ->number of vertex  and m -> number of edges
+    std::cin >> vertex >> edge;
+    // adj is 2-D vector to store edges between vertex
+    std::vector < std::vector < long int > > adj(vertex , std::vector <long int> ());
+    // color is use to store color of vertex
+    std::vector < long int > color(vertex , -1);
+    std::queue < long int > q;
+    // for number of edges times
+    for (int i=0;i < edge; ++i)
+    {
+        std::cin >> u >> v;
+        adj[u-1].push_back(v-1);
+        adj[v-1].push_back(u-1);
+    }
+    u=0;
+    color[u]=0;
+    q.push(u);
+    while (!q.empty())
+    {
+        counter=q.front();
+        q.pop();
+        for (auto i=adj[counter].begin();i!=adj[counter].end(); ++i)
+        {
+            // updating color of vertex
+            if (color[*i]==-1)
+            {
+                q.push(*i);
+                color[*i]=1-color[counter];
+            }
+            else if (color[*i]==color[counter])
+            {
+                flag=true;
+            }
+        }
+    }
+    if ( !flag )
+        std::cout << "Graph is bipartite" << "\n" ;
+    else
+        std::cout << "Graph is not bipartite" << "\n" ;
+}