Compilare: user.cpp: In function ‘void read()’: user.cpp:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void dfs(int)’: user.cpp:33: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:92: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:93: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:94: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result /usr/include/c++/4.4/bits/stl_algo.h: In function ‘void solve()’: /usr/include/c++/4.4/bits/stl_algo.h:2178: warning: array subscript is above array bounds