#include <stdio.h>

#define MAX 100

typedef int NODE;

typedef struct CELL *LIST;
struct CELL {
	NODE nodeName;
	LIST next;
};

enum MARKTYPE {VISITED, UNVISITED};

typedef struct {
	enum MARKTYPE mark;
	LIST successors;
	int postorder;
}  GRAPH[MAX];

int k; /* counts visited nodes */

void dfs(NODE u, GRAPH G)
{
	LIST p; /* points to cells of adjacency list of u */
	NODE v; /* the node in the cell pointed to by p */

	G[u].mark = VISITED;
	p = G[u].successors;
	while (p != NULL) {
		v = p->nodeName;
		if (G[v].mark == UNVISITED)
			dfs(v, G);
		p = p->next;
	}
	++k;
	G[u].postorder = k;
}

void dfsForest(GRAPH G)
{
	NODE u;

	k = 0;
	for (u = 0; u < MAX; u++)
		G[u].mark = UNVISITED;
	for (u = 0; u < MAX; u++)
		if (G[u].mark == UNVISITED)
			dfs(u, G);
}