Compilare: user.cpp: In function ‘void euler()’: user.cpp:28:53: warning: operation on ‘k’ may be undefined [-Wsequence-point] else{S[++k]=G[S[k-1]][G[S[k-1]].size()-1].first; ^ user.cpp: In function ‘void citire()’: user.cpp:10:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("ciclueuler.in","r",stdin); freopen("ciclueuler.out","w",stdout); ^ user.cpp:10:75: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("ciclueuler.in","r",stdin); freopen("ciclueuler.out","w",stdout); ^ user.cpp:11:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:13:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] { scanf("%d%d",&x,&y); ^