int dfs(IntList* adjVertices, IntList* trees, int* color, int v, int t) {
int w;
IntList* remAdj;
int ans = 0;
color[v] = grey;
time++;
discoverTime[v] = time;
remAdj = adjVertices[v];
int wAns = 0;
while (remAdj != intNil) {
w = intFirst(remAdj);
wAns = 0;
if(color[w] == white) {
parent[w] = v;
trees[t] = intCons(v , trees);
wAns = dfs(adjVertices, trees, color, w, t);
} else {
if(parent[w] == -1) wAns = 1;
break;
}
remAdj = intRest(remAdj);
}
time++;
finishTime[v] = time;
ans = wAns;
color[v] = black;
return ans;
}
//origGraph is array of IntLists to be transposed
//n is the size of origGraph
IntList* transposeGraph(IntList* origGraph, int n){
int i;
int s = 0;
IntList curr;
//find length of graph2 by finding max element of origGraph
for(i = 0; i < n; i++){
curr = origGraph[i];
while(curr != intNil){
if(intFirst(curr) > s)
s = intFirst(curr);
curr = intRest(curr);
}
}
//sets new size equal to the max element of the old array
if(s > size)
size = s;
//make and initialize graph2
IntList* graph2 = calloc(size , sizeof (IntList));
for(i = 0; i < n; i++){
graph2[i] = intNil;
}
//read origGraph and transpose to graph2
for(i = 0; i < n; i++){
curr = origGraph[i];
while(curr != intNil){
graph2[intFirst(curr)-1] = intCons(i + 1, graph2[intFirst(curr) - 1]);
curr = intRest(curr);
}
}return graph2;
}
int loadEdges(FILE* fp, char* inbuf, IntList* adjVertices, int n) {
int num;
Cstring line;
num=0;
line = fgets(inbuf, 1024, fp);
while (line != NULL) {
Edge e = parseEdge(line, n);
adjVertices[e.from] = intCons(e.to, adjVertices[e.from]);
num++;
line = fgets(inbuf, 1024, fp);
}
return num;
}
int main(int argc, char* argv[]){
FILE *fp;
fp = fopen(argv[1], "r"); //reads file
if(!fp){ //if no file
perror("No file specified"); //print error
return -1;
}
int size = atoi(fgets(line, 1000, fp)); //get the size of the array
printf("Array Size = %d \n", size); //print out first line aka size of array
//struct IntList * list = NULL;
IntList* array = calloc(size, sizeof(IntList)); //allocate space for array
char * stuff;
int m;
int n;
int ls;
int j;
int num = 0;
//array declaration start
int dTime1[size];
int fTime1[size];
int parent1[size];
int finishStk1[size];
//array declaration end
//initialize to null
for(j = 0; j <= size; j++){
array[j] = intNil;
}
while(fgets(line, 1000, fp) != NULL){ //while there is a line to read
stuff = strtok(line, " \t "); //stuff
ls = 0; //line stuff
while(stuff != NULL){ //keep goings
ls++; //next part on line
if(ls == 1){ //1st number
m = atoi(stuff);
}
if(ls == 2){ //2nd number
n = atoi(stuff);
if(m >= 0 && m <= size){
array[m-1] = intCons(n, array[m-1]);
num++;
}else printf("No edge for %d, %d\n", m, n);
}
stuff = strtok(NULL, " ,.-"); //stops the loop if nothing else is there
}
}
int i;
dfsSweep(array, size, dTime1, fTime1, parent1, finishStk1);
printf("Original Graph\n");
//print times and parent for all edges
for(i = 0; i < size; i++){
printf("Discover Time [%d]: %d\t", i+1, dTime1[i]);
printf("Finish Time [%d]: %d\t", i+1, fTime1[i]);
printf("Parent [%d]: %d \n", i+1, parent1[i]);
}
//print the order edges were visited
printf("Edges: ");
for(i = 0; i < size; i++){
printf("%d ", finishStk1[i]);
}
printf("\n");
//transpose the graph
IntList* transGraph = transposeGraph(array, size);
//print transposed graph
printf("\nTransposed Graph:\n");
//array declaration
int dTime2[size];
int fTime2[size];
int parent2[size];
int dfstRoot2[size];
dfsSweepT(transGraph, size, dTime2, fTime2, parent2, finishStk1, dfstRoot2);
//print times and parent for all edges
for(i = 0; i < size; i++){
printf("Discover Time [%d]: %d\t", i+1, dTime2[i]);
printf("Finish Time [%d]: %d\t", i+1, fTime2[i]);
printf("Parent [%d]: %d \n", i+1, parent2[i]);
}
//print the order edges were visited
printf("Edges: ");
for(i = 0; i < size; i++){
printf("%d ", dfstRoot2[i]);
}
printf("\n");
//close file and exit
fclose(fp);
return 0;
}
int main (int argc, char** argv)
{
if (argc == 1)
{
printf("Usage: graph01 input.data\n");
return 0;
}
// Create Array
char buffer [100];
bool in = false;
int n = 0, m = 0, to = 0, from = 0;
IntList* adjVertices;
FILE* the_file;
if (argc == 2 && strcmp(argv[1], "-") == 0)
{
the_file = stdin;
in = true;
}
else
the_file = fopen(argv[1], "r");
fgets(buffer, sizeof (buffer), the_file);
sscanf(buffer, "%d", &n);
adjVertices = calloc(n + 1, sizeof (struct IntListNode*));
for (int i = 1; i <= n; i++)
adjVertices[i] = intNil;
while (fgets(buffer, sizeof (buffer), the_file))
{
sscanf(buffer, "%d %d", &from, &to);
if (from < n + 1 && from > 0)
{
m++;
adjVertices[from] = intCons(to, adjVertices[from]);
}
}
if (in == false)
fclose(the_file);
// Print Array
printf("n = %d\nm = %d\n", n, m);
for (int i = 1; i <= n; i++)
{
printf("%d\t", i);
if (adjVertices[i] == intNil)
{
printf("null\n");
continue;
}
for (bool first = true; adjVertices[i] != intNil; adjVertices[i] = intRest(adjVertices[i]))
{
if (first == true)
{
first = false;
printf("[%d", intFirst(adjVertices[i]));
}
else
printf(", %d", intFirst(adjVertices[i]));
}
printf("]\n");
}
free(adjVertices);
}
