Compilare: user.cpp: In function ‘int main()’: user.cpp:41:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<coada.size()) ^ user.cpp:45:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<v[x].size()) ^ user.cpp:22:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.in","r",stdin); ^ user.cpp:23:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.out","w",stdout); ^ user.cpp:24:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&x); ^ user.cpp:27:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d" , &a[i].a , &a[i].b ); ^