Compilare: user.cpp: In function ‘int solve(int, int)’: user.cpp:31:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(dq.size()>k) ^ user.cpp:33:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(dq.size()==k) ^ user.cpp: In function ‘int main()’: user.cpp:61:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<vs.size(); ++i) ^ user.cpp:62:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i; j<vs.size(); ++j) ^ user.cpp:44:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("drept.in", "r", stdin); ^ user.cpp:45:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("drept.out", "w", stdout); ^ user.cpp:50:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:52:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^