GRAPH

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#define MAX 100

enum {WHITE, GREY , BLACK};

typedef struct vertex{

    int id;
    int color;
    int dist;
    int disc_time;
    int endP_time_;
    int pred;
    int scc;
    int *rowAdj;

}vertex;

typedef struct graph{
    vertex *g;
    int nv;
}graph;

// Function Prototypes
graph *graphLoad (char *filename);
int graphFind (graph *g, int id);
void graphAttributeInit (graph *g);
void graphDispose (graph *g);

// Main Function
int main(){
    graph *g = NULL;

    g = graphLoad("../input.txt");

    // Example: Print the adjacency matrix of the loaded graph
    printf("Adjacency Matrix:\n");
    for (int i = 0; i < g->nv; i++) {
        for (int j = 0; j < g->nv; j++) {
            printf("%d ", g->g[i].rowAdj[j]);
        }
        printf("\n");
    }

    // Example: Find and print the index of a vertex with ID 2
    int index_2 = graphFind(g, 2);
    if (index_2 != -1) {
        printf("Index of vertex with ID 2: %d\n", index_2);
    } else {
        printf("Vertex with ID 2 not found.\n");
    }

    graphDispose(g);

    graphDispose(g);
    return EXIT_SUCCESS;

}

// Function Declarations
graph *graphLoad (char *filename) {
    graph *g;
    char line[MAX];
    int i, j, weight, dir;

    FILE *fp;
    g = (struct graph *) malloc( sizeof(graph));
    if(g == NULL){
        fprintf(stderr,"memory allocation failed\n");
        exit(EXIT_FAILURE);
    }


    fp = fopen(filename, "r");
    if(fp == NULL){
        fprintf(stderr,"memory allocation failed\n");
        exit(EXIT_FAILURE);
    }

    fgets (line, MAX, fp);


    if (sscanf(line, "%d %d", &g->nv, &dir) != 2) {
        sscanf(line, "%d", &g->nv);
        dir = 1;
    }

    g->g = (struct vertex *) malloc(g->nv * sizeof(vertex));
    if(g->g == NULL){
        fprintf(stderr,"memory allocation failed\n");
        exit(EXIT_FAILURE);
    }

    for (i=0; i<g->nv; i++) {
        g->g[i].id = i;
        g->g[i].color = WHITE;
        g->g[i].dist = INT_MAX;
        g->g[i].pred = -1;
        g->g[i].scc = -1;
        g->g[i].disc_time = -1;
        g->g[i].rowAdj = (int *) malloc (g->nv * sizeof(int));
    }
    while (fgets(line, MAX, fp) != NULL) {
        if (sscanf(line, "%d%d%d", &i, &j, &weight) != 3) {

            sscanf(line, "%d%d", &i, &j);
            weight = 1;
        }

        g->g[i].rowAdj[j] = weight;
        if (dir == 0) {
            g->g[j].rowAdj[i] = weight;
        }
    }

    fclose(fp);
    return g;
}


void graphAttributeInit (graph *g) {
    int i;
    for (i=0; i<g->nv; i++) {
        g->g[i].color = WHITE;
        g->g[i].dist = INT_MAX;
        g->g[i].disc_time = -1;
        g->g[i].endP_time_ = -1;
        g->g[i].pred = -1;
        g->g[i].scc = -1;
    }

    return;
}

int graphFind (graph *g, int id){
    int i;
    for (i=0; i<g->nv; i++) {

        if (g->g[i].id == id) {
            return i;
        }

    }
    return -1;
}


void graphDispose (graph *g) {
    int i;
    for (i=0; i< g->nv; i++) {
        free(g->g[i].rowAdj);
    }
    free(g->g);
    free(g);

    return;
}