Compilare: main.cpp: In function 'int dfs(int, int)': main.cpp:125:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int& i = last[node]; i < graph[node].size(); ++i) ~~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:195:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < edges.size(); ++i) ~~^~~~~~~~~~~~~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:18:38: 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, 4096, fin); ^