// Loads a (directed, undirected or multi) graph from a text file InFNm with 1 node and all its edges in a single line.
void IOConnList() {
const int NNodes = 500;
const int NEdges = 2000;
const char *FName = "demo.graph.dat";
PNEGraph GOut, GIn;
GOut = GenRndGnm<PNEGraph>(NNodes, NEdges);
// Create graph file
FILE *F = fopen(FName, "w");
for (TNEGraph::TNodeI NI = GOut->BegNI(); NI < GOut->EndNI(); NI++) {
fprintf(F, "%d", NI.GetId());
for (int i = 0; i < NI.GetOutDeg(); i++) {
fprintf(F, " %d", NI.GetOutNId(i));
}
fprintf(F, "\n");
}
fclose(F);
// Load edge list
GIn = LoadConnList<PNEGraph>(FName);
PrintGStats("ConnList - Out", GOut);
PrintGStats("ConnList - In", GIn);
}
// Save and load directed, undirected and multi-graphs, where node names are strings
void IOEdgeListStr() {
const int NNodes = 1000;
const int NEdges = 5000;
const char *FName = "demo.graph.dat";
PNEGraph GOut, GIn; // Can also be PUNGraph or PNGraph
GOut = GenRndGnm<PNEGraph>(NNodes, NEdges);
// Output nodes as random strings
TIntStrH OutNIdStrH;
TStrHash<TInt> OutStrNIdH;
// Generate unique random strings for graph
TStr RandStr;
for (TNEGraph::TNodeI NI = GOut->BegNI(); NI < GOut->EndNI(); NI++) {
do {
RandStr.Clr();
TInt RandLen = TInt::Rnd.GetUniDevInt(5, 30);
for (int i = 0; i < RandLen; i++) {
TStr RandChar(TInt::Rnd.GetUniDevInt(33, 126));
RandStr += RandChar;
}
}
while (OutStrNIdH.IsKey(RandStr) || RandStr[0] == '#'); // Not unique or starts with comment
OutNIdStrH.AddDat(NI.GetId(), RandStr);
OutStrNIdH.AddDat(RandStr, NI.GetId());
}
// Create graph file
FILE *F = fopen(FName, "w");
for (TNEGraph::TEdgeI EI = GOut->BegEI(); EI < GOut->EndEI(); EI++) {
TInt Src = EI.GetSrcNId();
TInt Dst = EI.GetDstNId();
fprintf(F, "%s %s\n", OutNIdStrH[Src].CStr(), OutNIdStrH[Dst].CStr());
}
fclose(F);
// Load edge list of strings
TStrHash<TInt> InStrToNIdH;
GIn = LoadEdgeListStr<PNEGraph>(FName, 0, 1, InStrToNIdH);
PrintGStats<PNEGraph>("EdgeListStr - Out", GOut);
PrintGStats<PNEGraph>("EdgeListStr - In", GIn);
}
// Test node, edge creation
TEST(TNEGraph, ManipulateNodesEdges) {
int NNodes = 1000;
int NEdges = 100000;
const char *FName = "test.graph";
PNEGraph Graph;
PNEGraph Graph1;
PNEGraph Graph2;
int i;
int n;
int NCount;
int x,y;
int Deg, InDeg, OutDeg;
Graph = TNEGraph::New();
EXPECT_EQ(1,Graph->Empty());
// create the nodes
for (i = 0; i < NNodes; i++) {
Graph->AddNode(i);
}
EXPECT_EQ(0,Graph->Empty());
EXPECT_EQ(NNodes,Graph->GetNodes());
// create random edges
NCount = NEdges;
while (NCount > 0) {
x = (long) (drand48() * NNodes);
y = (long) (drand48() * NNodes);
n = Graph->AddEdge(x, y);
NCount--;
}
EXPECT_EQ(NEdges,Graph->GetEdges());
EXPECT_EQ(0,Graph->Empty());
EXPECT_EQ(1,Graph->IsOk());
for (i = 0; i < NNodes; i++) {
EXPECT_EQ(1,Graph->IsNode(i));
}
EXPECT_EQ(0,Graph->IsNode(NNodes));
EXPECT_EQ(0,Graph->IsNode(NNodes+1));
EXPECT_EQ(0,Graph->IsNode(2*NNodes));
// nodes iterator
NCount = 0;
for (TNEGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
NCount++;
}
EXPECT_EQ(NNodes,NCount);
// edges per node iterator
NCount = 0;
for (TNEGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
for (int e = 0; e < NI.GetOutDeg(); e++) {
NCount++;
}
}
EXPECT_EQ(NEdges,NCount);
// edges iterator
NCount = 0;
for (TNEGraph::TEdgeI EI = Graph->BegEI(); EI < Graph->EndEI(); EI++) {
NCount++;
}
EXPECT_EQ(NEdges,NCount);
// node degree
for (TNEGraph::TNodeI NI = Graph->BegNI(); NI < Graph->EndNI(); NI++) {
Deg = NI.GetDeg();
InDeg = NI.GetInDeg();
OutDeg = NI.GetOutDeg();
EXPECT_EQ(Deg,InDeg+OutDeg);
}
// assignment
Graph1 = TNEGraph::New();
*Graph1 = *Graph;
EXPECT_EQ(NNodes,Graph1->GetNodes());
EXPECT_EQ(NEdges,Graph1->GetEdges());
EXPECT_EQ(0,Graph1->Empty());
EXPECT_EQ(1,Graph1->IsOk());
// saving and loading
{
TFOut FOut(FName);
Graph->Save(FOut);
FOut.Flush();
}
{
TFIn FIn(FName);
Graph2 = TNEGraph::Load(FIn);
}
EXPECT_EQ(NNodes,Graph2->GetNodes());
EXPECT_EQ(NEdges,Graph2->GetEdges());
EXPECT_EQ(0,Graph2->Empty());
EXPECT_EQ(1,Graph2->IsOk());
// remove all the nodes and edges
for (i = 0; i < NNodes; i++) {
n = Graph->GetRndNId();
Graph->DelNode(n);
}
EXPECT_EQ(0,Graph->GetNodes());
EXPECT_EQ(0,Graph->GetEdges());
EXPECT_EQ(1,Graph->IsOk());
EXPECT_EQ(1,Graph->Empty());
Graph1->Clr();
EXPECT_EQ(0,Graph1->GetNodes());
EXPECT_EQ(0,Graph1->GetEdges());
EXPECT_EQ(1,Graph1->IsOk());
EXPECT_EQ(1,Graph1->Empty());
}