Merge pull request #168 from somya51p/solis

isGraphBipartite algorithm added

Author: smv1999

Data Structures/Graphs/isGraphBipartite.cpp

@@ -0,0 +1,44 @@
+/*  ' Is Graph Bipartite ' problem from Leetcode
+
+    A graph is bipartite if the nodes can be partitioned into two independent sets A and B
+    such that every edge in the graph connects a node in set A and a node in set B.
+
+    The main function is predefined. Here is the code to the question.
+*/
+
+
+class Solution {
+public:
+
+    vector<int> color;
+    bool dfs(int node, vector<vector<int>> &graph){
+        for(auto child: graph[node]){
+            if(color[child] != -1){
+                if(color[child] == color[node])
+                    return false;
+                continue;
+            }
+            color[child] = (color[node] + 1)%2;
+            if(!dfs(child, graph)) 
+                return false;
+        }
+        return true;
+    }
+    
+    bool isBipartite(vector<vector<int>>& graph) {
+        int n = graph.size();
+        color = vector<int> (n, -1);
+        for(int node=0; node<n; node++){
+            if(color[node]==-1){
+                color[node] = 0;
+                if(!dfs(node, graph)) return false;
+            }
+        }
+        return true;
+    }
+};
+
+/*
+    Input: graph = [[1,2,3],[0,2],[0,1,3],[0,2]]
+    Output: false
+*/