Compilare: user.cpp: In function ‘int main()’: user.cpp:27:38: warning: narrowing conversion of ‘i’ from ‘int’ to ‘short int’ inside { } [-Wnarrowing] a[g[i][j]].push_back({i,j}); ^ user.cpp:27:38: warning: narrowing conversion of ‘j’ from ‘int’ to ‘short int’ inside { } [-Wnarrowing] user.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<a[v[i]].size();j++) ^ user.cpp:16:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sarpe2.in","r",stdin); ^ user.cpp:17:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sarpe2.out","w",stdout); ^ user.cpp:18:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:19:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&m); ^ user.cpp:21:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^ user.cpp:26:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&g[i][j]); ^