Compilare: user.cpp: In function ‘void add(int, int)’: user.cpp:52:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v1.size();i++) reuneste(v1[i],node[a][b]); ^ user.cpp: In function ‘int main()’: user.cpp:73:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<poz[i].size();j++) add(poz[i][j].first,poz[i][j].second);\ ^ user.cpp:76:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<poz[i].size();j++) ^ user.cpp:82:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<poz[i].size();j++) ^ user.cpp:90:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<poz[down].size();j++) ^ user.cpp:57:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mexc.in","r",stdin); ^ user.cpp:58:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mexc.out","w",stdout); ^ user.cpp:60:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&d); ^ user.cpp:64:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x1); ^