Compilare: user.cpp: In function ‘void bfs()’: user.cpp:13:12: warning: variable ‘v’ set but not used [-Wunused-but-set-variable] int i,k,j,v[nmax],b; ^ user.cpp:13:20: warning: unused variable ‘b’ [-Wunused-variable] int i,k,j,v[nmax],b; ^ user.cpp: In function ‘int main()’: user.cpp:57:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ;j < V[P[i]].size()&&!ok;j++){ ^ user.cpp:33:16: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(in); ^ user.cpp:34:17: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(out); ^ user.cpp:35:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&xi,&yi); ^ user.cpp:37:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^