Compilare: user.cpp: In function ‘int main()’: user.cpp:63:36: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 3 has type ‘int’ [-Wformat=] if (xx==0) fprintf(g,"%ld\n",-1); ^ user.cpp:42:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%ld %ld\n", &n, &sum); ^ user.cpp:44:46: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1; i<=n; i++) fscanf(f,"%ld", &a[i]); ^