Compilare: user.c:1:1: warning: data definition has no type or storage class [enabled by default] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c:1:1: warning: type defaults to ‘int’ in declaration of ‘b’ [enabled by default] user.c:1:3: warning: return type defaults to ‘int’ [enabled by default] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c: In function ‘main’: user.c:1:3: warning: type of ‘a’ defaults to ‘int’ [enabled by default] user.c:1:1: warning: implicit declaration of function ‘fscanf’ [-Wimplicit-function-declaration] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c:1:11: warning: incompatible implicit declaration of built-in function ‘fscanf’ [enabled by default] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c:1:1: warning: implicit declaration of function ‘fopen’ [-Wimplicit-function-declaration] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c:1:1: warning: passing argument 1 of ‘fscanf’ makes pointer from integer without a cast [enabled by default] user.c:1:1: note: expected ‘void *’ but argument is of type ‘int’ user.c:1:1: warning: implicit declaration of function ‘fprintf’ [-Wimplicit-function-declaration] user.c:1:56: warning: incompatible implicit declaration of built-in function ‘fprintf’ [enabled by default] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c:1:1: warning: passing argument 1 of ‘fprintf’ makes pointer from integer without a cast [enabled by default] b;main(a){fscanf(fopen("adunare.in","r"),"%d%d",&a,&b);fprintf(fopen("adunare.out","w"),"%d",a+b);} ^ user.c:1:1: note: expected ‘void *’ but argument is of type ‘int’