connected.c

/*	connected.c

	Compute the connected components of a graph.

	by: Steven Skiena
	begun: March 6, 2002
*/

/*
Copyright 2003 by Steven S. Skiena; all rights reserved. 

Permission is granted for use in non-commerical applications
provided this copyright notice remains intact and unchanged.

This program appears in my book:

"Programming Challenges: The Programming Contest Training Manual"
by Steven Skiena and Miguel Revilla, Springer-Verlag, New York 2003.

See our website www.programming-challenges.com for additional information.

This book can be ordered from Amazon.com at

http://www.amazon.com/exec/obidos/ASIN/0387001638/thealgorithmrepo/

*/

#include <stdio.h>

#include "bool.h"
#include "bfs-dfs.h"

extern bool processed[];    /* which vertices have been processed */
extern bool discovered[];   /* which vertices have been found */
extern int parent[];        /* discovery relation */

void process_vertex(int v) {
    printf(" %d", v);
}

void process_vertex_early(int v) {
    printf(" %d", v);
}

void process_vertex_late(int v) {

}

void process_edge(int x, int y) {

}

/* [[[ cc_cut */
void connected_components(graph *g) {
    int c;              /* component number */
    int i;              /* counter */

    initialize_search(g);

    c = 0;
    for (i = 1; i <= g->nvertices; i++) {
        if (discovered[i] == FALSE) {
            c = c + 1;
            printf("Component %d:", c);
            bfs(g, i);
            printf("\n");
        }
    }
}
/* ]]] */

int main(void) {
    graph g;

    read_graph(&g, FALSE);
    print_graph(&g);

    connected_components(&g);

    return 0;
}