Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:39: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:73: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 2 has type ‘size_t’ user.cpp:74: warning: comparison between signed and unsigned integer expressions user.cpp:57: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:58: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:60: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:63: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result