Compilare: user.cpp: In function ‘int main()’: user.cpp:82:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < pos2.size(); i++) { ^ user.cpp:104:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++) { ^ user.cpp:106:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < v.size() - 1; j++) ^ user.cpp:14:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trenul.in","r",stdin); ^ user.cpp:15:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trenul.out","w",stdout); ^ user.cpp:22:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&c); ^