Compilare: user.cpp: In function ‘int main()’: user.cpp:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<sons[nd].size();j++) ^ user.cpp:40:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<sons[ord[i]].size();j++) ^ user.cpp:45:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<lvl[lv].size();i++) ^ user.cpp:48:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<fth[nd].size();j++) ^ user.cpp:56:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<lvl[lv].size();i++) ^ user.cpp:63:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<sons[nd].size();j++) ^ user.cpp:10:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pm2.in","r",stdin); ^ user.cpp:11:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pm2.out","w",stdout); ^ user.cpp:12:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:13:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) scanf("%d",&val[i]); ^ user.cpp:16:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); ^ user.cpp:19:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^