Compilare: user.c: In function ‘main’: user.c:40:13: warning: implicit declaration of function ‘abs’ [-Wimplicit-function-declaration] d1=abs(A[i].x-B[j].x); ^ user.c:42:13: warning: implicit declaration of function ‘max’ [-Wimplicit-function-declaration] S=S+max(d1,d2); ^ user.c:44:5: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘long long int’ [-Wformat=] fprintf(fout,"%d\n",S); ^ user.c:18:11: warning: unused variable ‘y’ [-Wunused-variable] int x,y,d1,d2,i,j; ^ user.c:18:9: warning: unused variable ‘x’ [-Wunused-variable] int x,y,d1,d2,i,j; ^ user.c: In function ‘abs’: user.c:50:5: warning: type of ‘x’ defaults to ‘int’ [enabled by default] int abs(x) ^ user.c: In function ‘main’: user.c:20:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.c:21:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&m); ^ user.c:24:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&A[i].x); ^ user.c:25:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&A[i].y); ^ user.c:29:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&B[i].x); ^ user.c:30:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&B[i].y); ^