Compilare: user.cpp: In function ‘void unite()’: user.cpp:23:28: warning: unused variable ‘lt’ [-Wunused-variable] int rt = st[S].first , lt = rt - st[S].second + 1; ^ user.cpp:24:32: warning: unused variable ‘ln’ [-Wunused-variable] int rn = st[S - 1].first , ln = rn - st[S - 1].second + 1; ^ user.cpp: In function ‘int main()’: user.cpp:34:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permsplit.in" , "r" , stdin); ^ user.cpp:35:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permsplit.out" , "w" , stdout); ^ user.cpp:37:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ user.cpp:40:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &a[i]); ^