Compilare: user.c: In function ‘main’: user.c:24:5: warning: implicit declaration of function ‘exit’ [-Wimplicit-function-declaration] exit(0); ^ user.c:24:5: warning: incompatible implicit declaration of built-in function ‘exit’ [enabled by default] user.c:29:5: warning: incompatible implicit declaration of built-in function ‘exit’ [enabled by default] exit(1); ^ user.c:8:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x,&y); ^