day 14

Author: sachuverma

Diff for: .vscode/settings.json

@@ -0,0 +1,11 @@
+{
+  "files.associations": {
+    "array": "cpp",
+    "bitset": "cpp",
+    "string_view": "cpp",
+    "initializer_list": "cpp",
+    "regex": "cpp",
+    "utility": "cpp",
+    "valarray": "cpp"
+  }
+}

Diff for: Leetcode Daily Challenge/February-2021/14. Is Graph Bipartite.cpp

@@ -0,0 +1,73 @@
+/*
+Is Graph Bipartite?
+===================
+
+Given an undirected graph, return true if and only if it is bipartite.
+
+Recall that a graph is bipartite if we can split its set of nodes into two independent subsets A and B, such that every edge in the graph has one node in A and another node in B.
+
+The graph is given in the following form: graph[i] is a list of indexes j for which the edge between nodes i and j exists. Each node is an integer between 0 and graph.length - 1. There are no self edges or parallel edges: graph[i] does not contain i, and it doesn't contain any element twice.
+
+Example 1:
+Input: graph = [[1,3],[0,2],[1,3],[0,2]]
+Output: true
+Explanation: We can divide the vertices into two groups: {0, 2} and {1, 3}.
+
+Example 2:
+Input: graph = [[1,2,3],[0,2],[0,1,3],[0,2]]
+Output: false
+Explanation: We cannot find a way to divide the set of nodes into two independent subsets.
+
+Constraints:
+1 <= graph.length <= 100
+0 <= graph[i].length < 100
+0 <= graph[i][j] <= graph.length - 1
+graph[i][j] != i
+All the values of graph[i] are unique.
+The graph is guaranteed to be undirected. 
+*/
+
+class Solution
+{
+public:
+  bool bfs(int curr, vector<vector<int>> &graph, vector<int> &color)
+  {
+    queue<int> pending;
+    pending.push(curr);
+    color[curr] = 1;
+
+    while (pending.size())
+    {
+      auto curr = pending.front();
+      pending.pop();
+      for (auto &i : graph[curr])
+      {
+        if (color[i] != -1 && color[i] != 1 - color[curr])
+          return false;
+        else if (color[i] == -1)
+        {
+          color[i] = 1 - color[curr];
+          pending.push(i);
+        }
+      }
+    }
+    return true;
+  }
+
+  bool isBipartite(vector<vector<int>> &graph)
+  {
+    int n = graph.size();
+    vector<int> color(n, -1);
+
+    for (int i = 0; i < n; ++i)
+    {
+      if (color[i] == -1)
+      {
+        if (!bfs(i, graph, color))
+          return false;
+      };
+    }
+
+    return true;
+  }
+};

Diff for: Leetcode Daily Challenge/February-2021/README.MD

@@ -15,5 +15,6 @@
 | 11.  | [Valid Anagram](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3636/) | [cpp](./11.%20Valid%20Anagram.cpp) | 
 | 12.  | [Number of Steps to Reduce a Number to Zero](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3637/) | [cpp](./12.%20Number%20of%20Steps%20to%20Reduce%20a%20Number%20to%20Zero.cpp) | 
 | 13.  | [Shortest Path in Binary Matrix](https://leetcode.com/explore/challenge/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3638/) | [cpp](./13.%20Shortest%20Path%20in%20Binary%20Matrix.cpp) | 
+| 14.  | [Is Graph Bipartite?](https://leetcode.com/explore/featured/card/february-leetcoding-challenge-2021/585/week-2-february-8th-february-14th/3639/) | [cpp](./14.%20Is%20Graph%20Bipartite.cpp) |