//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 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;
}
Cstring toCharR(Cstring prefix, IntList L) {
Cstring s = calloc(1024, sizeof(char));
if(L == intNil) {
s[0] = ']';
} else {
strncpy(s, prefix, 1024);
strncat(s, (Cstring)intFirst(L), 1024);
strncat(s, toCharR(", ", intRest(L)), 1024);
return s;
}
}
Cstring toCharR(Cstring prefix, IntList L) {
Cstring s = calloc(1024, sizeof(char));
if(L == intNil) {
s = "]";
} else {
char intF[10];
sprintf(intF, "%d", intFirst(L));
strncpy(s, prefix, 1024);
strncat(s, intF, 1024);
strncat(s, toCharR(", ", intRest(L)), 1024);
}
return s;
}
int main (int argc, char** argv)
{
if (argc == 1)
{
printf("Usage: graph01 input.data\n");
return 0;
}
/* CREATE ADJACENCY LISTS */
int n = 0, m = 0, result;
IntList* adj_list; IntList* transpose_list;
adj_list = loadGraph(&n, &m, argc, argv);
transpose_list = fix_graph(transposeGraph(adj_list, n), n);
int discoverTime1[n], finishTime1[n], finishStk[n], parent1[n], counter = 1, stackspot = n;
memset(discoverTime1, 0, n * sizeof(int));
memset(finishTime1, 0, n * sizeof(int));
memset(finishStk, 0, n * sizeof(int));
memset(parent1, -1, n * sizeof(int));
int discoverTime2[n], finishTime2[n], dfstRoot[n], parent2[n];
memset(discoverTime2, 0, n * sizeof(int));
memset(finishTime2, 0, n * sizeof(int));
memset(parent2, -1, n * sizeof(int));
memset(dfstRoot, 0, n * sizeof(int));
for (int i = 1; i <= n; i++)
result = dfsTrace1(adj_list, discoverTime1, finishTime1, finishStk, parent1, &counter, i, &stackspot);
counter = 1;
for (int i = 0; i < n; i++)
result = dfsTrace2(transpose_list, discoverTime2, finishTime2, finishStk, parent2, &counter, finishStk[i], dfstRoot, finishStk[i]);
result = result;
/* ADJACENCY LIST */
printf("\n__Adjacency List__\n");
// print list
print_list(adj_list, n, m);
// display stack
printf("stack: [");
for (int i = 0; i < n; i++)
{
if (i != 0)
printf(", ");
printf("%d", finishStk[i]);
}
printf("]\n\n");
// table
printf("vertex |dtime |ftime |parent\n");
printf("-------|------|------|------\n");
for (int i = 0; i < n; i++)
printf("%7d|%6d|%6d|%6d\n", i + 1, discoverTime1[i], finishTime1[i], parent1[i]);
printf("\n\n");
/* TRANSPOSE LIST */
printf("__Transpose List__\n");
// print transpose list
print_list(transpose_list, n, m);
printf("\n");
// table
printf("vertex |dtime |ftime |parent |root\n");
printf("-------|------|------|-------|-----\n");
for (int i = 0; i < n; i++)
printf("%7d|%6d|%6d|%7d|%5d\n", i + 1, discoverTime2[i], finishTime2[i], parent2[i], dfstRoot[i]);
printf("\n");
/* FREE MEMORY */
for (int i = 1; i <= n; i++)
{
for (IntList ptr = adj_list[i]; ptr != intNil; ptr = intRest(ptr));
for (IntList ptr = transpose_list[i]; ptr != intNil; ptr = intRest(ptr));
}
free(adj_list);
free(transpose_list);
}
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);
}