Compilare: main.cpp: In function 'int main()': main.cpp:20:43: warning: format '%lld' expects argument of type 'long long int', but argument 3 has type 'int' [-Wformat=] fprintf( fout, "%lld", 2 * a * f[a] ); ^ main.cpp:16:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &n ); ^ main.cpp:19:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &a ); ^