Compilare: user.c: In function ‘main’: user.c:28:13: warning: implicit declaration of function ‘realloc’ [-Wimplicit-function-declaration] edge[from]=realloc(edge[from],(nr[from]+1)*sizeof(int)); ^ user.c:28:24: warning: incompatible implicit declaration of built-in function ‘realloc’ [enabled by default] edge[from]=realloc(edge[from],(nr[from]+1)*sizeof(int)); ^ user.c:44:21: warning: incompatible implicit declaration of built-in function ‘realloc’ [enabled by default] edge[i]=realloc(edge[i],0); ^ user.c:15:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("easygraph.in","r",stdin); ^ user.c:16:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("easygraph.out","w",stdout); ^ user.c:18:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&t); ^ user.c:21:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&n,&m); ^ user.c:23:23: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] fr(i,0,n)scanf("%i",val+i); ^ user.c:26:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&from,&to); ^