# include<stdio.h>
# include<conio.h >
#define NIL -1
enum c{white=-5,gray,black};
int n;
int d[6],f[6],a[6],time;
int graph[6][6]={{0,1,0,0,0,1},{0,0,0,0,1,0},{0,0,0,1,1,0},{0,0,0,0,0,0},{0,0,0,0,0,0},{0,1,0,0,1,0}};
int color[6],pred[6];
int gt[6][6],k=6;
void DFS_VISIT(int u)
{
int v;
color[u]=gray;
time++;
d[u]=time;
for(v=0;v<6;v++)
{
if(graph[u][v]!=0)
{
if(color[v]==white)
{
pred[v]=u;
DFS_VISIT(v);
}
}
}
color[u]=black;
printf("%4d",u);
 f[u]=++time;
 a[k-1]=u;
 k--;
}
void transpose()// Transpose Graph
{
 int i,j;
 for(i=0;i<6;i++)
 {
 for(j=0;j<6;j++)
 {
 gt[i][j]=graph[j][i];
 }
 }
}
void dfs2(int u) // DFS of Transposed Graph, u=a[i], Parameter is nodes finished in decr order
{
 int j;
 color[u]=black;
 for(j=0;j<6;j++)
 {
 if(gt[u][j]!=0)
 {
 if(color[j]==white)
 dfs2(j);
 }
 }
 printf("%d\t",u);
}
int main()
{
 int i,j,count=0;;
time=0;
for(i=0;i<6;i++) // Initialize
{
color[i]=white;
pred[i]=NIL;
}
printf("\nThe DFS traversal of the graph as:\n\n");
for(i=0;i<6;i++)
{
if(color[i]==white)
DFS_VISIT(i); // call DFS_Visit(u)
}
 printf("\n\n\nThe discovery & finishing time of the vertices are:\n\n\n");
 for(i=0;i<6;i++)
 {
 printf("For vertex %d : \td[%d]=%d f[%d]=%d\n",i,i,d[i],i,f[i]);
 }
 transpose();
 for(i=0;i<6;i++) // initialize for SCC
 {
 color[a[i]]=white;
 }
 for(i=0;i<6;i++)
 {
 if(color[a[i]]==white)
 {
 count++;
 printf("\n\nStrongly Connected Component %d --> ",count);
 dfs2(a[i]);
 }
}
getch();
return 0;
}