Eroare de compilare: user.c: In function ‘main’: user.c:10:13: error: ‘a’ undeclared (first use in this function) for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:10:13: note: each undeclared identifier is reported only once for each function it appears in user.c:10:17: error: ‘b’ undeclared (first use in this function) for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:10:16: warning: left-hand operand of comma expression has no effect [-Wunused-value] for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:10:21: error: ‘r’ undeclared (first use in this function) for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:10:20: warning: left-hand operand of comma expression has no effect [-Wunused-value] for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:10:32: warning: left-hand operand of comma expression has no effect [-Wunused-value] for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:10:36: warning: left-hand operand of comma expression has no effect [-Wunused-value] for(a=j,b=i,r=a%b;r;a=b,b=r,r=a%b); ^ user.c:5:12: 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:5:50: 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:5:88: 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); ^