Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:52:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < v[ x ].size(); ++i ){ ^ user.cpp:43:9: warning: unused variable ‘n’ [-Wunused-variable] int n, i, y, c; ^ user.cpp:43:15: warning: unused variable ‘y’ [-Wunused-variable] int n, i, y, c; ^ user.cpp: In function ‘int main()’: user.cpp:18:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fof.in","r",stdin); ^ user.cpp:19:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fof.out","w",stdout); ^ user.cpp:23:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:25:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^