Compilare: user.cpp: In function ‘int main()’: user.cpp:52:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ user.cpp:68:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vt[nod].size();i++) ~^~~~~~~~~~~~~~~ user.cpp:81:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[v1[i]].size();j++) ~^~~~~~~~~~~~~~~~ user.cpp:97:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[nod].size();j++) ~^~~~~~~~~~~~~~ user.cpp:33:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("shuffle2.in","r",stdin); ^ user.cpp:34:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("shuffle2.out","w",stdout); ^ user.cpp:36:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:41:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^