Compilare: user.cpp: In function ‘void Find(int)’: user.cpp:13:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:42:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < pos[i].size(); ++j) ^ user.cpp:23:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nivele2.in","r",stdin); ^ user.cpp:24:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nivele2.out","w",stdout); ^ user.cpp:28:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:31:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&A,&B); ^