Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:14:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) dfs(v[nod][i].first); ^ user.cpp:18:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[nod].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:33:11: warning: unused variable ‘x’ [-Wunused-variable] int t,x,n; ^ user.cpp:31:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oxificarelight.in","r",stdin); ^ user.cpp:32:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oxificarelight.out","w",stdout); ^ user.cpp:34:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:37:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:39:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n;i++) scanf("%d",&cost[i]); ^