एक द्विदलीय ग्राफ एक ग्राफ है जिसमें यदि दो रंगों का उपयोग करके ग्राफ को रंगना संभव है; एक समुच्चय के शीर्षों को एक ही रंग से रंगा जाता है। यह एक C++ प्रोग्राम है जो यह जांचने के लिए है कि ग्राफ़ द्विदलीय है या 2 रंग एल्गोरिथम का उपयोग नहीं कर रहा है।
कार्य और छद्म कोड
Begin 1. Develop function isSafe() to check if the current color assignment is safe for vertex v, i.e. checks whether the edge exists or not. If it exists, then next check whether the color to be filled in the new vertex is already used by its adjacent vertices. 2. function graphColoringtil(bool g[V][V], int k, int col[], int v) : g[V][V] = It is a 2D array where V is the number of vertices in graph k = maximum number of colors that can be used. col[] = an color array that should have numbers from 1 to m. if v == V return true For c = 1 to k if (isSafe(v, g, col, c)) col[v] = c if (graphColoringtil (g, k, col, v+1) == true) return true col[v] = 0 return false 3.function graphColoring(bool g[V][V], int k): for i = 0 to V-1 color[i] = 0 if (graphColoringtil(g, k, color, 0) == false) return false return true
उदाहरण
#include <iostream> #include <cstdio> #define V 4 using namespace std; bool isSafe (int v, bool g[V][V], int col[], int C) //to solve m coloring //problem { for (int i = 0; i < V; i++) if (g[v][i] && C == col[i]) return false; return true; } bool graphColoringtil(bool g[V][V], int k, int col[], int v) { if (v == V) //If all vertices are assigned a color then return true; for (int c = 1; c <= k; c++) //Consider this vertex v and try different colors { if (isSafe(v, g, col, c)) //Check if assignment of color c to v is fine { col[v] = c; if (graphColoringtil (g, k, col, v+1) == true) //recur to assign colors to rest of the vertices return true; col[v] = 0; //If assigning color c doesn't lead to a solution then remove it } } return false; }
आउटपुट
The graph is Bipartite