Compilare: user.cpp: In function ‘int main()’: user.cpp:15:16: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp:7:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("perechi3.in", "r", stdin); ^ user.cpp:8:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("perechi3.out", "w", stdout); ^ user.cpp:10:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &t); ^ user.cpp:13:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &n); ^