int main()
{
int t;
scanf("%d",&t);
while(t--)
{
int E,i,j;
scanf("%d %d",&V,&E);
int G[V][V];
int a,b;
for(i=0;i<V;i++)
for(j=0;j<V;j++)
G[i][j]=0;
while(E--)
{
scanf("%d %d",&a,&b);
a--;
b--;
G[a][b]=1;
G[b][a]=1;
}
isBipartite(G, 0) ? printf("YES\n") : printf("NO\n");
}
return 0;
}
bool isBipartite(int root, Colors* verticesColors)
{
auto edge = edges[root];
while (edge != nullptr)
{
if (verticesColors[edge->verticeTo] == Colors::Undefined)
{
if (verticesColors[root] == Colors::Red)
{
verticesColors[edge->verticeTo] = Colors::Black;
}
else
{
verticesColors[edge->verticeTo] = Colors::Red;
}
if (isBipartite(edge->verticeTo, verticesColors) == false)
{
return false;
}
edge = edge->next;
}
else if (verticesColors[edge->verticeTo] == verticesColors[root])
{
return false;
}
}
return true;
}
int main(int main, char* argv[])
{
auto graph = new Graph(4);
graph->addEdge(1, 2);
graph->addEdge(1, 3);
graph->addEdge(1, 4);
graph->addEdge(2, 4);
std::cout << "Graph should not be bipartite: " << graph->isBipartite() << std::endl;
graph = new Graph(5);
graph->addEdge(1, 2);
graph->addEdge(1, 3);
graph->addEdge(2, 4);
graph->addEdge(4, 5);
std::cout << "Graph should be bipartite: " << graph->isBipartite() << std::endl;
}
void BicoloringAnalizer::analizeGraphs(string fileName)
{
int numOfVertices;
int numOfEdges;
int vertex;
int adjacentVertex;
std::ifstream input;
input.exceptions(std::ios_base::failbit | std::ios_base::badbit);
try {
input.open(fileName, std::ios_base::in);
input >> numOfVertices;
while (numOfVertices != 0) {
if (numOfVertices < 2 || numOfVertices > 199) {
input.close();
throw std::runtime_error("Wrong number of nodes. Must be \"1 < nodes < 200\"\n");
}
input >> numOfEdges;
if (numOfEdges < 1) {
input.close();
throw std::runtime_error("Wrong data in file.\n");
}
graph.clear();
graph.resize(numOfVertices);
for (int i = 0; i < numOfEdges; i++) {
input >> vertex >> adjacentVertex;
if (vertex >= 0 && vertex < numOfVertices && adjacentVertex >= 0 && adjacentVertex < numOfVertices)
graph[vertex].push_back(adjacentVertex);
else {
input.close();
throw std::runtime_error("Wrong vertex label. Must be \"0 <= vertex_label < numOfVertices\"\n");
}
}
if (isBipartite(numOfVertices))
std::cout << "BICOLORABLE." << std::endl;
else
std::cout << "NOT BICOLORABLE." << std::endl;
input >> numOfVertices;
}
}
catch (std::ios_base::failure) {
std::cerr << "Error reading file: ";
input.close();
throw;
}
input.close();
}
bool isBipartite()
{
Colors *verticesColors = (Colors*)malloc((numberOfVertices + 1)*sizeof(Colors));
memset(verticesColors, 0, (numberOfVertices + 1)*sizeof(Colors));
for (auto i = 1; i < numberOfVertices; ++i)
{
if (verticesColors[i] == Colors::Undefined)
{
verticesColors[i] = Colors::Red;
if (isBipartite(i, verticesColors) == false)
{
return false;
}
}
}
return true;
}
int main() {
std::vector<std::vector<int>> test = {{1,2}, {0,2}, {0,1}};
std::cout << "Is bipartite? " << isBipartite(test) << std::endl;
return 0;
}
