Compilare: user.cpp: In function ‘int main()’: user.cpp:12:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("invazia.in", "r", stdin); ^ user.cpp:13:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("invazia.out", "w", stdout); ^ user.cpp:40:40: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] for (l = last_index; l < last_index + k; ++l) { ^ user.cpp:23:6: warning: ‘last_index’ may be used uninitialized in this function [-Wmaybe-uninitialized] int last_index; ^