C ++程序使用2色算法检查图是否为二分图
二分图是其中可以使用两种颜色进行着色的图形，即：一组顶点的颜色相同。这是一个C++程序，使用2色算法检查图形是否为二分图。
函数和伪代码
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示例
#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;
}输出结果
The graph is Bipartite