Compilare: user.c: In function ‘main’: user.c:15:21: warning: variable ‘z’ set but not used [-Wunused-but-set-variable] int n,m,k,c,i,j,z; ^ user.c:16:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d %d %d\n",&n,&m,&k,&c); ^ user.c:18:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d %d %d",&x1[i],&y1[i],&x2[i],&y2[i]); ^