Compilare: user.cpp: In function ‘int main()’: user.cpp:89:29: warning: too many arguments for format [-Wformat-extra-args] fprintf(out, "lld\n", suma); ^ user.cpp:48:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &a, &b); ^ user.cpp:49:27: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(line, linemax, in); ^ user.cpp:50:27: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(line, linemax, in); ^