Compilare: user.cpp: In function ‘int readInt()’: user.cpp:24: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘void read()’: user.cpp:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘void dfs(int)’: user.cpp:50: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs2(int)’: user.cpp:72: warning: comparison between signed and unsigned integer expressions user.cpp:78: warning: comparison between signed and unsigned integer expressions user.cpp:83: warning: suggest parentheses around comparison in operand of ‘|’ user.cpp: In function ‘void dfs3(int)’: user.cpp:95: warning: comparison between signed and unsigned integer expressions user.cpp:102: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:139: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:140: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result