Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:29:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<A[x].size();++i) ^ user.cpp: In function ‘void drumda(int)’: user.cpp:48:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<A[x].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:68:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marmelada.in","r",stdin); ^ user.cpp:69:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("marmelada.out","w",stdout); ^ user.cpp:70:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&n,&m,&S,&D); ^ user.cpp:73:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^ user.cpp:84:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&f[i].val); ^