从结构数组访问值

Question

I'm trying to use an array of a the structure 'sommet', as defined below.

typedef struct sommet {
double x;
double y;
char nom[100];
struct arete2* voisin;};

sommet* somtab = (sommet *) calloc(nbnoeud, sizeof(sommet));
if(somtab = NULL){
    puts("Calloc error");
    exit(1);
}

In my code I have three separate arrays, xtab, ytab and nomtab, that respectively contain the x, y, and nom values for the somtab element of equivalent index (ie somtab[0].x = xtab[0], somtab[1].x = xtab[1] etc.) When come to set each of the somtab elements my programme breaks down and I never make it to "check3"

puts("check1");

for(a=0; a<nbnoeud; a++){
    printf("Read item %d; \t \t \t %s - (%lf, %lf). \n", a, nomtab[a], xtab[a], ytab[a]);
}

puts("check2");

for(a=0; a<nbnoeud; a++){
    somtab[a].x = xtab[a];
    somtab[a].y = ytab[a];
    strcpy(somtab[a].nom, nomtab[a]);
}

puts("check3");

Answer 1

Use a pointer to a pointer.

sommet** somtab = malloc(nbnoeud*sizeof(sommet));

use

    somtab[a]->x = xtab[a];
    somtab[a]->y = ytab[a];
    strcpy(somtab[a]->nom, nomtab[a]);