Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:16:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i<a[x].size(); ++i) ^ user.cpp: In function ‘void countMax(int, int, int, int)’: user.cpp:41:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i<a[x].size(); ++i) ^ user.cpp:67:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i<a[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:90:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("asmin.in","r",stdin); ^ user.cpp:91:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("asmin.out","w",stdout); ^ user.cpp:93:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&k); ^ user.cpp:98:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^ user.cpp:105:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&r[i]); ^