Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:17:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i<g[X].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:42:9: warning: unused variable ‘nivfin’ [-Wunused-variable] int nivfin = niv[Y]; ^ user.cpp:32:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in","r",stdin); ^ user.cpp:33:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out","w",stdout); ^ user.cpp:34:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d\n",&n,&m,&X,&Y); ^ user.cpp:37:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^