Compilare: user.cpp: In function ‘void {anonymous}::dfs(int)’: user.cpp:125:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < g[u].size(); ++i) ~~^~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:172:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("craciun.in", "r", stdin); ^ user.cpp: In function ‘char {anonymous}::nextch()’: user.cpp:154:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, BMAX, stdin); ^