Compilare: user.cpp: In function ‘int main()’: user.cpp:42:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<G[nod].size(); j++) ^ user.cpp:69:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0; k<G[nod].size() && ok==0; k++) ^ user.cpp:9:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen("alpin.in", "r", stdin); ^ user.cpp:10:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alpin.out", "w", stdout); ^ user.cpp:11:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:14:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^