Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:21: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:63: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:64: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:68: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:30: warning: dereferencing pointer ‘<anonymous>’ does break strict-aliasing rules /usr/include/c++/4.4/bits/stl_tree.h:250: note: initialized from here user.cpp:38: warning: dereferencing pointer ‘<anonymous>’ does break strict-aliasing rules /usr/include/c++/4.4/bits/stl_tree.h:250: note: initialized from here user.cpp:20: warning: ‘ermin’ may be used uninitialized in this function user.cpp:20: warning: ‘ermax’ may be used uninitialized in this function