Compilare: main.cpp: In function 'int main()': main.cpp:79:59: warning: value computed is not used [-Wunused-value] printf("%lld\n", (MOD + solve(1e9) - solve(6e8)) % MOD )<< '\n'; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~ main.cpp:74:12: warning: unused variable 't' [-Wunused-variable] long long t,a ,b; ^ main.cpp:74:14: warning: unused variable 'a' [-Wunused-variable] long long t,a ,b; ^ main.cpp:74:17: warning: unused variable 'b' [-Wunused-variable] long long t,a ,b; ^ main.cpp:76:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("invinv.out", "w", stdout); ^