Compilare: user.cpp: In function ‘int main()’: user.cpp:17:15: warning: unused variable ‘sol’ [-Wunused-variable] long long sol = 0; ^ user.cpp:12:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("twoton.in", "r", stdin); ^ user.cpp:13:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("twoton.out", "w", stdout); ^ user.cpp:15:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.cpp:20:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^