Compilare: user.cpp: In function ‘int bfs()’: user.cpp:23:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:61:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[dest].size();i++) ~^~~~~~~~~~~~~~~ user.cpp:82:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<g[i].size();j++) ~^~~~~~~~~~~~ user.cpp:37:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algola.in","r",stdin); ^ user.cpp:38:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algola.out","w",stdout); ^ user.cpp:40:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:43:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:51:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^