Eroare de compilare: user.c: In function ‘main’: user.c:9:21: error: ‘r’ undeclared (first use in this function) for(a=i,b=j,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:9:21: note: each undeclared identifier is reported only once for each function it appears in user.c:9:36: warning: left-hand operand of comma expression has no effect [-Wunused-value] for(a=i,b=j,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:6:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelograme.in","r",stdin),freopen("paralelograme.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:6:50: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelograme.in","r",stdin),freopen("paralelograme.out","w",stdout),scanf("%d%d",&n,&m); ^ user.c:6:88: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelograme.in","r",stdin),freopen("paralelograme.out","w",stdout),scanf("%d%d",&n,&m); ^