Eroare de compilare: user.c: In function ‘main’: user.c:11:5: warning: implicit declaration of function ‘scau’ [-Wimplicit-function-declaration] freopen("cartele.in","r",stdin),freopen("cartele.out","w",stdout),scau("%d%d",&n,&c); ^ user.c:11:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cartele.in","r",stdin),freopen("cartele.out","w",stdout),scau("%d%d",&n,&c); ^ user.c:11:44: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cartele.in","r",stdin),freopen("cartele.out","w",stdout),scau("%d%d",&n,&c); ^ /tmp/cc3jmy2K.o: In function `main': user.c:(.text.startup+0x5b): undefined reference to `scau' user.c:(.text.startup+0xa8): undefined reference to `scau' user.c:(.text.startup+0x138): undefined reference to `scau' collect2: error: ld returned 1 exit status