Create isBipartiteGraph.hpp

include/CXXGraph/Graph/Algorithm/isBipartiteGraph.hpp

@@ -0,0 +1,87 @@
+/***********************************************************/
+/***      ______  ____  ______                 _         ***/
+/***     / ___\ \/ /\ \/ / ___|_ __ __ _ _ __ | |__      ***/
+/***    | |    \  /  \  / |  _| '__/ _` | '_ \| '_ \     ***/
+/***    | |___ /  \  /  \ |_| | | | (_| | |_) | | | |    ***/
+/***     \____/_/\_\/_/\_\____|_|  \__,_| .__/|_| |_|    ***/
+/***                                    |_|             ***/
+/***********************************************************/
+/***     Header-Only C++ Library for Graph               ***/
+/***   Representation and Algorithms                     ***/
+/***********************************************************/
+/***     Author: ZigRazor ***/
+/***    E-Mail: zigrazor@gmail.com                       ***/
+/***********************************************************/
+/***    Collaboration: -----------                       ***/
+/***********************************************************/
+/***    License: AGPL v3.0 ***/
+/***********************************************************/
+
+#ifndef __CXXGRAPH_CHECK_ODD_NODES_CYCLE_H__
+#define __CXXGRAPH_CHECK_ODD_NODES_CYCLE_H__
+
+#pragma once
+
+#include "CXXGraph/Graph/Graph_decl.h"
+
+namespace CXXGraph {
+
+template <typename T>
+class Graph {
+public:
+    TopoSortResult<T> checkOddNodesCycleDir() const;
+
+private:
+    void checkOddNodesCycleUtil(std::vector<int>& visited, std::vector<int>& chainNo, 
+                                int root, int cycleLength, bool &isBiPartite) const;
+};
+
+template <typename T>
+TopoSortResult<T> Graph<T>::checkOddNodesCycleDir() const {
+    TopoSortResult<T> result;
+
+    // Check if the graph is undirected
+    if (isDirectedGraph()) {
+        result.errorMessage = ERR_UNDIR_GRAPH; // Error: Graph is directed
+        return result;
+    }
+
+    const auto nodeSet = Graph<T>::getNodeSet();
+    std::vector<int> visited(nodeSet.size(), 0);
+    std::vector<int> chainNo(nodeSet.size(), -1);
+    bool isBiPartite = true;
+
+    for (const auto& node : nodeSet) {
+        if (!visited[node->getId()]) {
+            visited[node->getId()] = 1;
+            checkOddNodesCycleUtil(visited, chainNo, node->getId(), 0, isBiPartite);
+            if (!isBiPartite) {
+                result.errorMessage = "The graph contains an odd-length cycle.";
+                return result;
+            }
+        }
+    }
+
+    result.success = true;
+    return result;
+}
+
+template <typename T>
+void Graph<T>::checkOddNodesCycleUtil(std::vector<int>& visited, std::vector<int>& chainNo, 
+                                      int root, int cycleLength, bool &isBiPartite) const {
+    chainNo[root] = cycleLength;
+    for (const auto& child : cachedAdjMatrix->at(root)) {
+        if (!visited[std::get<0>(child)->getId()]) {
+            visited[std::get<0>(child)->getId()] = 1;
+            checkOddNodesCycleUtil(visited, chainNo, std::get<0>(child)->getId(), cycleLength + 1, isBiPartite);
+            if (!isBiPartite) return;
+        } else if (chainNo[root] == chainNo[std::get<0>(child)->getId()]) {
+            isBiPartite = false;
+            return;
+        }
+    }
+}
+
+}  // namespace CXXGraph
+
+#endif  // __CXXGRAPH_CHECK_ODD_NODES_CYCLE_H__