C++ Program to Check whether Graph is a Bipartite using 2 Color Algorithm

C++Server Side ProgrammingProgramming

A bipartite graph is a graph in which if the graph coloring is possible using two colors i.e.; vertices in a set are colored with the same color. This is a C++ program to Check whether a graph bipartite or not using 2 color algorithm.

Functions and pseudocodes

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

Example

#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;
}

Output

The graph is Bipartite
raja
Published on 26-Apr-2019 07:08:04
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